exam 1 quizzes

Question 1

A free-body diagram displays

a. the weight distribution of a body on a surface
b. the pressure distribution of a body on a surface
c. the mass distribution of a body
d. the forces acting on a body
e. none of the above

Answer 1

d

Question 2

if two forces lying in the same plane are added together and the result is zero, which of the following is true
a. they are opposite in direction
b. they are equal in magnitude
c. both a and b
d. none of the above

Answer 2

c

Question 3

the force that a acts parallel to an object in contact with a surface is called
a. friction force
b. normal contact force
c. internal force
d. colinear force
e. resolved force

Answer 3

a

Question 4

a force can be
a. push
b. pull
c. a or b
d. simultaneously push and pull
e. none of the above

Answer 4

c

Question 5

to fully define a vector you must specify
a. length and magnitude
b. length and area
c. area and direction
d. direction and magnitude
e. none of the above

Answer 5

d

Question 6

velocity is calculated as
a distance/time
b. displacement/time
c. force/time
d. force x distance
e. force/distance

Answer 6

b

Question 7

at 3s into a run, a football player is traveling at +3m/s. four seconds later, the player is traveling at -5m/s. the change in velocity is equal to
a. +2 m/s
b. -2m/s
c. +3m/s
d. -8m/s
e. +8m/s

Answer 7

d

Question 8

when a runner has completed one full lap around a 400m track, what is the runners displacement with respect to the starting position
a. 400m
b. 400m multiplied by 2pi
c. zero
d. need more information

Answer 8

c

Question 9

a swimmer traveling with an average velocity of -3.2m/s. how far does the swimmer travel in 3s
a. 1.1m
b. 6.9m
c. 9.6m
d. a swimmer cannot travel in the negative direction
e. need more info

Answer 9

c

Question 10

the horizontal velocity of Serena’s tennis serve is measured as 112mi/h (50m/s). horizontally, the ball travels 82ft (25m) before reaching Venus. If the ball didn’t slow down when it bounced or because of air resistance how long would it take to reach Venus?
a. .25s
b. .75s
c. .50s
d. 1s
e. 2s

Answer 10

c

Question 11

as the mass of an object increases, what happens to its inertia
a. decrease
b. increase
c. stays the same
d. weighs more
e. mass and inertia are not related

Answer 11

b

Question 12

to start in motion an object sitting at rest on a horizontal surface, the horizontal force applied must be
a. greater than vertical
b. less than vertical
c. greater than the weight of the object
d. less than the weight of the object
e. none of the above

Answer 12

e

Question 13

a net horizontal force of 200N is applied to a wrestler of mass 100kg. the horizontal acceleration of the wrestler will be
a. 200m/s^2
b. 100m/s^2
c. 2m/s^2
d. 1m/s^2
e. need more information

Answer 13

c

Question 14

a high jumper with a body weight of 820 N exerts an average vertical force of 1640 N down on the floor for .75s. the average vertical force exerted on the jumper by the floor is
a. 615 N
b. 820 N
c. 1230N
d. 1640N
e. 3280N

Answer 14

d

Question 15

a 60kg dancer applies a horizontal force of -800N on the dance floor. the dancers acceleration will be
a. -7.5m/s^2
b. 7.5m/s^2
c. -13.33m/s^2
d. 13.33
e. need more info

Answer 15

d

Question 16

mechanical work is performed in all of these types of muscle activity (contraction) except for
a. isometric
b. concentric
c. eccentric
d. mechanical work is performed in all of the above
e. mechanical work is not performed in any of the above

Answer 16

a

Question 17

a person performs a bench press. the bars mass is 50kg. when this person’s arms are extended, the bar is .6 m above the starting point. how much work did the person do to push the bar off his chest to full extension of his arms
a. 0Nm
b. 300Nm
c. -300Nm
d. 600Nm
e. -600Nm

Answer 17

b

Question 18

during the pitching motion, a baseball pitcher exerted an average horizontal force of 80N against the .15 baseball while moving it through a horizontal displacement of 2.0m before release. the amount of work performed by the pitcher on the baseball was
a. 40J
b. 80J
c. 82J
d. 160J
e. 320J

Answer 18

d

Question 19

if a 25kg child climbs two steps of 20cm each, the work performed is
a. 10Nm
b. 100Nm
c. 1000Nm
d. 10,000 Nm
e. need more info

Answer 19

b

Question 20

the capacity for doing work that a body possesses because of its position or configuration is known as
a. potential energy
b. kinetic energy
c. moment of inertia
d. power
e. torque

Answer 20

a

Question 21

torque is defined as
a. the tendency of a force to cause rotation
b. the turning affect of a force
c. the products of force and moment arm
d. all of the above
e. none of the above

Answer 21

d

Question 22

as a joint is moved through its ROM when strength training with free weights, such as doing the arm curl, the moment arm for the muscle crossing the joint will get
a. longer
b. shorter
c. either a or b
d. none of the above

Answer 22

c

Question 23

if the moment arm is 5cm and the force is 100N, the magnitude of the torque will be
a. 5Nm
b. 50Nm
c. 500Nm
d. 5000Nm
e. need more info

Answer 23

a

Question 24

stability may be increased by
a. raising the center of mass
b. decreasing the number of contact points in the base of support
c. widening the base of support perpendicular to any oncoming force
d. leaning away from an oncoming force
e. none of the above

Answer 24

e

Question 25

what happens to your center of gravity when you add a 200N suitcase to your hand held out to your side
a. shifts in the direction of the suitcase
b. shifts in the direction opposite of the suitcase
c. does not move
d. moves outside your body
e. need more info

Answer 25

a