The drawing shows three blocks, each with the same mass, stacked one upon the other. The bottom block rests on a frictionless horizontal surface and is being pulled by a force   that is parallel to this surface. The surfaces where the blocks touch each other have identical coefficients of static friction. Which one of the following correctly describes the magnitude of the net force of static friction fs that acts on each block?

fs,A = fs,C = fs,B/2
fs,A = fs,B = fs,C
fs,C = 0 and fs,A = fs,B/2
fs,A = fs,B = fs,C/2
fs,A = 0 and fs,B = fs,C/2
This answer states that the net frictional force acting on block C is zero, which implies that the surfaces where blocks B and C are in contact are frictionless. However, these surfaces have a coefficient of static friction, so a frictional force must act on block C.
B is incorrect: This answer states that the net frictional forces acting on blocks A and C have the same magnitude. However, a greater frictional force acts on block C than on block A, because the normal force pressing blocks B and C together is greater than the normal force pressing blocks A and B together.
A is incorrect: This answer states that the net frictional forces acting on blocks A and C have the same magnitude. However, a greater frictional force acts on block C than on block A, because the normal force pressing blocks B and C together is greater than the normal force pressing blocks A and B together.
E is incorrect: This answer states that the net frictional force acting on block A is zero, which implies that the surfaces where blocks A and B are in contact are frictionless. However, these surfaces have a coefficient of static friction, so a frictional force must act on block A.
C is incorrect: This answer states that the net frictional force acting on block C is zero, which implies that the surfaces where blocks B and C are in contact are frictionless. However, these surfaces have a coefficient of static friction, so a frictional force must act on block C.
D is correct: The static frictional force that blocks A and B exert on each other has a magnitude f. The force that B exerts on A is directed to the right (the positive direction), while the force that A exerts on B is directed to the left. Blocks B and C also exert static frictional forces on each other, but these forces have a magnitude 2f, because the normal force pressing B and C together is twice the normal force pressing A and B together. The force that C exerts on B is directed to the right, while the force that B exerts on C is directed to the left. In summary, then, block A experiences a single frictional force +f, which is the net frictional force; block B experiences two frictional forces, f and +2f, the net frictional force being f +2f = +f; block C experiences a single frictional force +2f, which is the net frictional force. It follows that fs,A = fs,B = fs,C/2.
Three identical blocks are being pulled or pushed across a horizontal surface by a force  , as shown in the drawings. The force   in each case has the same magnitude. Rank the kinetic frictional forces that act on the blocks in ascending order (smallest first).

B, A, C
A, C, B
C, B, A
C, A, B
B, C, A
E is incorrect: This answer states that the kinetic frictional force is smaller in C than in A. The magnitude of the frictional force is proportional to the magnitude of the normal force. However, the normal force in C is greater than the block’s weight due to the vertical component of  , whereas the normal force in A is equal to the block’s weight. Therefore, the frictional force in C is greater, not smaller, than in A.
B is incorrect: This answer states that the kinetic frictional force is smaller in C than in B. The magnitude of the frictional force is proportional to the magnitude of the normal force. However, the normal force in C is greater than the block’s weight due to the vertical component of  , whereas the normal force in B is less than the block’s weight due to the vertical component of  . Therefore, the frictional force in C is greater, not smaller, than in B.
C is correct: The magnitude of the kinetic frictional force is proportional to the magnitude of the normal force. The normal force is smallest in B, because the vertical component of   compensates for part of the block’s weight. In contrast, the normal force is greatest in C, because the vertical component of   adds to the weight of the block.

A heavy block is suspended from a ceiling using pulleys in three different ways, as shown in the drawings. Rank the tension in the rope that passes over the pulleys in ascending order (smallest first).

B is correct: More pulleys, less tension on rope.  In B the tension T is the smallest, because three rope segments support the weight W of the block, with the result that 3T = W, or T = W/3. In A the tension is the greatest, because only one rope segment supports the weight of the block, with the result that T = W.

Advertisements

Human Anatomy Things to know

Articulate – create a joint

process – projections on bone that form joints or points of attachment

Tuberosity – Rough, bumpy surface or projection

Tubercle – rounded projection. A tube is round in shape

Trochanter: Very large projection

Foramen: Hole for blood vessels or nerves. Foramina is the plural form.

Fossa: depression for bones to articulate.

Fissure – narrow slits in bone for blood vessels and nerves

Spinous process – pointed, sharp projections

Condyle – Large, rounded bulges with a smooth articular surface at the end of bones

Epicondyle – Rough bugles that are superior (above) to the condyle

Meatus – rounded passageways for blood vessels. Look like a tube of blood vessels surrounded by meat

Sulcus – Grooves in bone

Head – rounded at end of bones to connect to a joint

Line – Long narrow ridge or border

Crest – more prominent than a line.

Facet – smooth, flat, articular surface

 

 

Human Anatomy Chapter 7

Your upper teeth are embedded in which bone? maxilla

The roof of your mouth (hard palate) is formed by which two bones? palantine and maxilla

Which of the following bones does NOT form part of the orbit (eye socket)? nasal

Which of the following bones contains paranasal sinuses? ethmoid

Which bone contains the external auditory meatus? temporal

Which two bones contribute to forming the nasal septum? vomer and ethmoid

A: occipital condyle

B: mastoid process

C. jugular foramen

D. palantine

E. pterogoid process of the sphenoid bone (keystone bone)

Olfactory nerves travel through small holes in which bone? ethmoid

The spinal cord passes through the vertebral foramen in each vertebra.

C1: atlas

What is one feature that you can find in ALL cervical vertebrae but not in thoracic or lumbar? transverse foramen

The placement of hands directly on the body of the sternum is very important during CPR to avoid breaking the xiphoid (inferior portion of the sternum) located just inferior to the sternal body.

 

Human Anatomy Chapter 8

Which bones make up the pectoral girdle? clavicle and scapula

The ulna is located in the forearm on the medial side (i.e. “pinky” side). True

This feature is the coranoid process

False. It is the acromion

When you palpate your shoulder, the highest point you feel is the acromion process.

The roughened section on the humerus where the deltoid muscle attaches is called the deltoid tuberosity.

The slightly raised, roughened, V-shaped area on the middle portion of the diaphysis of the humerus is the deltoid tuberosity.

The olecranon process is located on the distal end and posterior side of the humerus. False

At the elbow joint, the radius articulates (connects) with: the capitulum of the humurus

The projection on the medial and posterior aspect of your wrist is formed by the: styloid process of the ulna

The bony pelvis is composed of which bones? sacrum, two od vocsr, and the pubic symphysis

The head of the femur fits into the acetabulum a depression or socket in the hip bone.

The projection on the lateral surface of your ankle is formed by which structure? lateral malleolus (small mallet or hammer) of the fibula.

If you break the end bone of the big toe you have damaged the 1st distal phalanx

If you break the end bone of the big toe you have damaged the ________________
X A. first distal phalanx
O B. first metatarsal
O C. fifth proximal phalynx
O D. talus

FEEDBACK

Congratulations, your answer is correct!
CORRECT 15.
This feature is the greater sciatic notch

X A. True
O B. False

FEEDBACK

Congratulations, your answer is correct!
CORRECT 16.
This depression is known as the acetabulum

X A. True
O B. False

FEEDBACK

Congratulations, your answer is correct!
CORRECT 17.
This region is the superior ramus of the pubis

O A. True
X B. False

FEEDBACK

Congratulations, your answer is correct!
WRONG 18.
Lateral to your umbilicus, the projection you can palpate from the surface that people usually call your “hip bone” is actually what?
O A. ischial spines
X B. pubic symphysis
O C. acetabulum
C D. iliac crests

FEEDBACK

Sorry, that’s not correct. See the section called Bones of the Pelvic Girdle.
WRONG 19.
When you are sitting, your weight is resting on the:
O A. iliac crest
C B. ischial tuberosities
O C. ischial spines
X D. sacrum

FEEDBACK

Sorry, that’s not correct. See the section called Bones of the Pelvic Girdle.
WRONG 20.
Male and female pelves differ in all of the following ways EXCEPT:
C A. pubic arch in males is > 90 degrees
X B. female pelvis is wider and shallower
O C. males have a more rounded obturator foramen
O D. females have a rounder pelvic inlet

FEEDBACK

Sorry, that’s not correct. See the section called Comparison of Female and Male Pelves.
CORRECT 21.
Another name for the knee joint is the __________ joint.
O A. tibiofibular
X B. tibiofemoral
O C. fibulofemoral
O D. fibulotarsal

FEEDBACK

Congratulations, your answer is correct!
WRONG 22.
The sharp line along the anterior surface of your lower leg (your shin) is formed by the anterior crest of the fibula.
X A. True
C B. False

FEEDBACK

Sorry, that’s not correct. See the section called Skeleton of the Leg—Tibia and Fibula.
CORRECT 23.
The ‘ankle bone’ at the distal end of the tibia is the tibial tuberosity.
O A. True
X B. False

FEEDBACK

Congratulations, your answer is correct!
WRONG 24.
All of the following bones are tarsals EXCEPT:
X A. talus
O B. calcaneus
C C. trapezoid
O D. navicular

FEEDBACK

Sorry, that’s not correct. See the section called Skeleton of the Foot.
WRONG 25.
Your “heel” bone is the:
X A. talus
O B. navicular
O C. cuboid
C D. calcaneus

FEEDBACK

Sorry, that’s not correct. See the section called Skeleton of the Foot.

Retake Test

Human Anatomy Notes Chapter 6

Briefly describe the processes involved in healing a bone fracture.
(1) A fracture hematoma forms at the injury site. (2) An internal callus forms as spongy bone unites the inner surfaces. An external callus of toughened connective tissue stabilizes the outer edges. (3) The external callus ossifies, and trabecular bone unites the broken ends. Dead bone closest to the break is removed and replaced. (4) The initial swelling of the external callus is eventually remodeled so that the repair site is only slightly thicker than the original bone.
Compare osteoporosis and osteopenia.
Osteoporosis and osteopenia both involve weakening of bone. The first is a disorder; the second is a normal occurrence. Both osteoporosis and osteopenia are most commonly associated with aging, the former more prevalent in women. Osteopenia is caused by a reduction in osteoblast activity.
What are canaliculi, and why are they important?
Canaliculi, the hollow channels that penetrate the lamellae of both compact and spongy bone, are essential for the survival of the osteocytes. By interconnecting the lacunae with the blood supply, they allow the transfer of nutrients and wastes through an otherwise impenetrable solid matrix.
Don thinks his left arm is weaker than his right because he broke his left humerus a few years ago. Is he likely correct? Why or why not?
The humerus that was broken is probably stronger than the one that never was broken. When completely healed, fracture sites typically withstand comparable stresses better than original bone.
Describe the trabeculae in spongy bone, and explain their functional significance.
Trabeculae are thin, often branching struts or plates composed of the concentric lamellae of spongy bone. They form an open, cross-braced framework that is light in weight but can resist stress from many directions. In addition, this framework protects and supports the cells of bone marrow.
How do bones grow in length?
Metaphyseal cartilage at each end of a long bone grows lengthwise toward the epiphyses and diaphyses while osteoblasts convert the inner (diaphyseal) surface of the epiphyseal plate to bone.
How does the “growth spurt” at puberty ultimately cause a person to stop growing taller?
The increase in sex hormones at puberty dramatically accelerates bone growth by stimulating osteoblasts. As the osteoblasts produce bone faster than the metaphyseal chondroblasts produce cartilage, the epiphyseal plates eventually ossify, and lengthwise growth ceases.
What vitamins most directly affect normal bone growth?
Vitamins A and C are essential for normal bone growth, and vitamin D is essential for enabling the digestive system to absorb calcium ions from the diet.
Name and describe the five types of nonarticulating processes found on bone surfaces.
(1) A trochanter is a large, rough projection. (2) A tuberosity is a smaller rough projection. (3) A tubercle is a small, rounded projection. (4) A crest is a prominent ridge. (5) A line is a low ridge. All of these are formed in places where tendons or ligaments attach to the periosteum of the bone.
Flat bone is composed of outer layers of compact bone known as inner and outer tables which sandwich a layer of spongy bone.
C A. True
X B. False

Flat bones are thin and composed f two nearly parallel plates of compact bone exposing a layer of spongy bone. Spony bones in the head are called diploe. They provide a lot of muscle attachment. Ex. cranial bones, sternum, ribs, scapulae.

The sternum is an example of a __________ bone.
O A. long
X B. short
C C. flat
O D. irregular
Compact bone has a regular arrangement of circular plates or layers arranged around a central canal. This concentric ring unit is called a(n):
C A. osteon
X B. lacunae
O C. canaliculi
O D. osteocytes
Compact bone has cells so tightly packed that there is no room for blood vessels.
X A. True
C B. False
Bones have a bit of flexibility to them due to the organic collagen fibers.
C A. True
X B. False
Strength of the area at the arrow is largely due to the arrangement of _______________ of the bone tissue making up this region.
O A. osteocytes
X B. lamellae
C C. trabeculae
O D. lacunae
Endochondral ossification begins with the formation of ossification centers in a(n)
O A. fibrocartilage callus
O B. epiphyseal plate
C C. hyaline cartilage model
X D. layer of spongy bone
Flat bones are formed by which type of osteogenesis?
O A. intrachondral ossification
X B. endochondral osteogenesis
O C. endomembranous osteogenesis
C D. intramembranous ossification

Intramembranous Ossification: Flatbones, facial bones, mandible, medial part of clavicle.

Exdochondrral: the rest of the  bones in the body

In the skeletal system, spongy bone is located:

Your Answer: in lining the canaliculi of bones.
Correct Answer: where stresses arrive from many directions.

A long bone increases in length by means of:

Your Answer: growth and ossification at the epiphyseal cartilage.

During intramembranous ossification, osteoblasts leave the area as bone is formed, leaving it exclusively as matrix.

Your Answer: False
Correct Answer: True

Small bones found in tendons: sesamoid bones

The periosteum:

Your Answer: lines the marrow cavity.
Correct Answer: contains an inner osteogenic layer.

Immovable fibrous joint that joins skull bones: suture

In a long bone, the epiphyseal plate functions to ensure that:

Your Answer: the bone can continue to increase in length.

Nasal septum = Perpendicular plate of ethmoid bone + Vomer

Osteopenia is a:

Your Answer: thickening of bone under the influence of unusual and heavy stresses.
Correct Answer: result of insufficient weight-bearing exercise, too little Vitamin D, and not enough calcium.

Membrane that covers cartilage: Perichondrium

Canal by which nerves and blood vessels penetrate into compact bone: Perforating canal.

Osteoporosis most severely reduces the ability of a bone to:

Your Answer: provide structural support for the body.

Processes that form where ligaments or tendons attach to a bone include:

Your Answer: trochanters, tuberosities and tubercles.

Mesenchyme-filled space where bone formation is not yet complete, especially between the cranial bones of an infant’s skull: fontanel

Depositon of mineral salts in a frameword formed by collagen fibers in which the tissue hardens: calcification.

A load that stresses a bone by pulling it in two different directions is __________.

Your Answer: tensile
Correct Answer: tension

The basic unit of structure in adult compact bone, consisting of a central (haversian) canal with its concentrically arranged lamellae, lacunae, osteocytes, and canaliculi. AKA Haversian system: Osteon

Small, hollow space, such as that found in bones in which the osteocytes lie: lacuna

Because they are strong and relatively inflexible, calcium phosphate crystals enable bone to withstand the stress of compression.

Ossification is the developmental process wherein mesenchyme or cartilage is replaced by bone.

Your Answer: False
Correct Answer: True
Your Answer: True

Mucus-lined air cavity in a skull bone that communicates with the nasal cavity. Paranasal sinuses are located in the frontal, maxillary, ethmoid, and sphenoid bones: paranasal sinus

Bone tissue consisting of trabeculae; found inside short, flat, and irregular bones and in the epiphyses (ends) of long bones.

7 bones of the ankle: Tarsals.

In the correct order, what are the steps involved in repair of a fracture in a bone?

Your Answer: An internal callus forms; it is remodeled, and once this is complete, the outer surface of the bone is remodeled.
Correct Answer: Blood forms a clot; a callus forms; its cartilage is replaced by new bone, and the old callus swelling is remodeled.

Microscopic tube running hte length of the spinal cord. Runs longitudinally in the center of an osteon of mature compact bone, containing blood and lymphatic vessels and nervesL Central canal.

Membrane that lines the medullary (marrow) cavity of bones, consisting of osteogenic cells and scattered osteoclasts.

A suture is a very complex junction between two bones of the skull that maximizes the area of ligamentous connection between the bones.

Your Answer: False
Correct Answer: True

Exaggeration of the thoracic curve of the vertebral column, resulting in a hunchback: kyphosis

A major difference between compact and spongy bone is that:

Your Answer: spongy bone lacks concentric lamellae.
Correct Answer: spongy bone lacks osteons.

Method of bone formation in which the bone is formed directly in messenchyme arranged sheet like layers that resemble membranes: Intramembranous ossification.

Stem cell derived from mesenchyme that has mitotic potential and the ability to differentiate into an osteoblast. Osteogenic cell.

8 bones of the wrist: Carpals.

Fused bones at the inferior end of the vertebral column: coccyx

Frontal plane = coronal plane

What are the four major sets of blood vessels in a typical bone?

Your Answer: Haversian artery, Volkmann’s artery and vein, and connecting capillaries
Correct Answer: nutrient artery and vein, epiphyseal vessels, metaphyseal vessels, and periosteal vessels

Slightly movable cartilaginous joint between the anterior surfaces of the hip bones. Pubic symphysis.

Joint in the skull between the parietal bones and the occipital bone, sometimes contains sutural bones: lambdoid suture.

Replacement of cartilage by bone. AKA intracartilaginous ossification: endochondral ossification

Small, irregularly shaped bones that sometimes form between bones of the skull are called ____________ bones.

Your Answer: sutural

7 bones of the ankle: tarsus

Exaggeration of the lumbar curve of the vertebral column. AKA hollow back: lordosis

Hyaline cartilage plate in the metaphysis of the long bone; site of lengthwise growth of long bones: epiphyseal plate

Space within the diaphysis of a bone that contains yellow bone marrow. AKA marrow cavity: Medullary cavity.

Growth due to surface deposition of material, as in the growth in diameter of cartilage and bone. AKA exogenous growth. Appositional growth.

8 bones of wrist: Carpals

A small channel or canal where they connect lacunae.

Which type of bone has an internal and external table of compact bone with a layer of spongy bone called the diploe in between?

Human Anatomy Practice Exams (Chapter 6, 7, 8)

Axial Skeleton: http://wps.pearsoncustom.com/pcp_72901_pls_martini_ha_5/78/20114/5149380.cw/index.html

http://wps.aw.com/bc_martini_fap_8_oa/93/23995/6142756.cw/index.html

Chapter Guide for Axial Skeleton: http://wps.aw.com/bc_martini_fap_8_oa/93/23995/6142756.cw/index.html

Cool, very useful Learning Activities for Axial Skeleton: http://wps.pearsoncustom.com/pcp_72901_pls_martini_ha_5/78/20114/5149380.cw/index.html

Bone Review: http://wps.pearsoncustom.com/pcp_72901_pls_martini_ha_5/78/20114/5149380.cw/index.html

Appendicular Division: http://wps.pearsoncustom.com/pcp_72901_pls_martini_ha_5/78/20115/5149513.cw/index.html

http://wps.aw.com/bc_martini_fap_8_oa/93/23995/6142890.cw/index.html

Chapter Guide for Appendicular Division: http://wps.aw.com/bc_martini_fap_8_oa/93/23995/6142890.cw/index.html

Cool, very useful Learning Activities for Appendicular Division: http://wps.pearsoncustom.com/pcp_72901_pls_martini_ha_5/78/20115/5149513.cw/index.html

Flashcards Quiz: http://bcs.wiley.com/he-bcs/Books?action=mininav&bcsId=6222&itemId=0470567058&assetId=235238&resourceId=23031&newwindow=true

Flashcards: http://media.pearsoncmg.com/bc/bc_martini_ha_5/flashcards/flashcards.html

Chapter Quizes: http://bcs.wiley.com/he-bcs/Books?action=resource&bcsId=6222&itemId=0470567058&resourceId=24297

Online Textbook and Human Anatomy Resource: http://www.getbodysmart.com/

 

Physics Notes and Practice Problems (Chapter 4 – Forces and Laws of Motion)

Practice Problems: http://wc.pima.edu/~solson/phy121/notes/notes18.pdf,

http://www.occc.edu/ktapp/gophysics/phys1114/PHYS1114_SP13_SampleExam3_Soln.pdf,

http://www.physics.rutgers.edu/ugrad/203f08/solutions/Week3,

http://www.solvephysics.com/dynamics_part1.shtml

http://www.solvephysics.com/dynamics_part2.shtml

An object is moving at a constant velocity. All but one of the following statements could be true. Which one cannot be true? A single force acts on the object. If only one force acts on the object, it is the net force; thus, the net force must be nonzero. Consequently, the velocity would change, according to Newton’s first law, and could not be constant.

Three forces act simultaneously on the object.

This statement could be true if the three forces had magnitudes and directions such that the vector sum of the three were zero. Then the net force would be zero, and the velocity would remain constant, according to Newton’s first law.

No forces act on the object. This statement could be true, because if no forces are acting, the net force is zero, and the velocity does not change, according to Newton’s first law.

Which one of the following is true, according to Newton’s laws of motion? Ignore friction.

Sam (18 years old) and his sister (9 years old) go ice skating. They push off against each other and fly apart. Sam flies off with the greater acceleration. This answer is false. According to the third law, Sam and his sister experience forces of equal magnitudes during the push-off. Since Sam has the greater mass, he flies off with the smaller acceleration, according to the second law.

A sports utility vehicle (SUV) hits a stationary motorcycle. Since it is stationary, the motorcycle sustains a greater force than the SUV does. This answer is false, according to the third law, which states that whenever one body exerts a force on a second body, the second body exerts an oppositely directed force of equal magnitude on the first body. It does not matter whether one of the bodies is stationary.

Two astronauts on a space walk are throwing a ball back and forth between each other. In this game of catch the distance between them remains constant. This answer is false because in catching and throwing the ball each astronaut applies a force to it, and, according to the third law, the ball applies an oppositely directed force of equal magnitude to each astronaut. These reaction forces accelerate the astronauts away from each other, so that the distance between them increases.

A semitrailer truck crashes all the way through a wall. Since the wall collapses, the wall sustains a greater force than the truck does. This answer is false, according to the third law, which states that whenever one body exerts a force on a second body, the second body exerts an oppositely directed force of equal magnitude on the first body. It does not matter whether one of the bodies collapses.

None of the these is true, according to the third law. Answers (a) and (b) are false, according to the third law, which states that whenever one body exerts a force on a second body, the second body exerts an oppositely directed force of equal magnitude on the first body. It does not matter whether one of the bodies is stationary or whether it collapses. Answer (c) is false because, according to the third law, Sam and his sister experience forces of equal magnitudes during the push-off. Since Sam has the greater mass, he flies off with the smaller acceleration, according to the second law. Answer (d) is false because in catching and throwing the ball each astronaut applies a force to it, and, according to the third law, the ball applies an oppositely directed force of equal magnitude to each astronaut. These reaction forces accelerate the astronauts away from each other, so that the distance between them increases.