From a mechanical perspective, it is easier to pull an object than to push it.
Answer: true
From a mechanical perspective, it is easier to pull an object than to push it.
Answer: true
Answer: true
A motionless object sitting on a motionless surface, with no horizontal force application, has no friction.
A motionless object sitting on a motionless surface, with no horizontal force application, has no friction.
Answer: true
Harder running surfaces result in greater ground reaction forces.
Harder running surfaces result in greater ground reaction forces.
Answer: false
Elite sprinters display greater impulse against the starting blocks than sub-elite sprinters.
Elite sprinters display greater impulse against the starting blocks than sub-elite sprinters.
Answer: true
New blade designs have resulted in extremely low values for the kinetic friction coefficients of ice hockey skates on ice.
New blade designs have resulted in extremely low values for the kinetic friction coefficients of ice hockey skates on ice.
Answer: true
An impact resulting in the total loss of velocity would be called a perfectly _______________ impact.
An impact resulting in the total loss of velocity would be called a perfectly _______________ impact.
Answer: plastic
Two common forces that act to reduce momentum are _______________ and _________________.
Two common forces that act to reduce momentum are _______________ and _________________.
Answer: friction, air resistance
Newton's law of acceleration demonstrates the relationship between acceleration, _______________ and ___________________.
Newton's law of acceleration demonstrates the relationship between acceleration, _______________ and ___________________.
Answer: force, mass
A number that serves as an index of elasticity for colliding bodies is called coefficient of ___________________.
A number that serves as an index of elasticity for colliding bodies is called coefficient of ___________________.
Answer: restitution
Newton's law of _______________ can be restated as the conservation of ________
Newton's law of _______________ can be restated as the conservation of ________
Answer: inertia, momentum
Which of the following is a correct unit of mechanical power?
Which of the following is a correct unit of mechanical power?
A. Joules
B. Watts
C. kg-m
D. kg/m
Answer: B
Which of the following is/are correct formula(s) for mechanical power?
Which of the following is/are correct formula(s) for mechanical power?
A. P = W/t
B. P = Fd/t
C. P = Fv
D. both A and B
E. all of the above
Answer: E
Negative mechanical work involves which of the following?
Negative mechanical work involves which of the following?
A. net torque and angular motion are same direction
B. net torque and angular motion are in different directions
C. concentric muscle contraction
D. none of the above
Answer: B
The formula for mechanical work is the product of which of the following?
The formula for mechanical work is the product of which of the following?
A. force and displacement
B. force and time
C. acceleration and time
D. power and displacement
Answer: A
Which of the following affects the coefficient of restitution between a tennis racket and tennis ball?
Which of the following affects the coefficient of restitution between a tennis racket and tennis ball?
A. how long the ball has been out of the can
B. how many times the ball has been hit
C. tightness of the grip
D. both A and B
E. all of the above
Answer: E
Which of the following is closest to a perfectly elastic impact?
Which of the following is closest to a perfectly elastic impact?
A. modeling clay dropped on a hard surface
B. modeling clay dropped on a trampoline
C. superball dropped on a hard surface
D. superball dropped on a trampoline
Answer: C
What happens to momentum when an impulse acts on a system?
What happens to momentum when an impulse acts on a system?
A. momentum is conserved
B. momentum is changed
C. impulse does not affect momentum
D. all of the above are possible
Answer: B
Which of the following is a correct unit for linear momentum?
Which of the following is a correct unit for linear momentum?
A. N·m
B. N·m/s
C. kg·m
D. kg·m/s
Answer: D
How does wearing gloves increase the friction between the hands and the bat?
How does wearing gloves increase the friction between the hands and the bat?
A. changes µk
B. changes µs
C. changes R
D. friction is not increased
Answer: B
How does adding weight to the back of a pickup increase the friction between the tires and the icy road?
How does adding weight to the back of a pickup increase the friction between the tires and the icy road?
A. changes µk
B. changes µs
C. changes R
D. friction is not increased
Answer: C
Which of the following relationships is always true?
Which of the following relationships is always true?
A. µk < µs
B. µs < µk
C. µk = µs
D. none of the above
Answer: A
Which of the following is/are true statement(s) regarding the law of gravitation?
Which of the following is/are true statement(s) regarding the law of gravitation?
A. All bodies are attracted to one another with a force proportional to the product of their masses.
B. All bodies are attracted to one another with a force inversely proportional to the square of the distance between them.
C. The law of gravitation ceases to exist outside the earth's atmosphere.
D. both A and B
E. all of the above
Answer: D
What is/are the direction(s) for vertical ground reaction force?
What is/are the direction(s) for vertical ground reaction force?
A. up
B. down
C. lateral
D. all of the above are possible directions
Answer: A
Which of the following would be typical for vertical ground reaction force (GRF) during running?
Which of the following would be typical for vertical ground reaction force (GRF) during running?
A. GRF = body weight
B. GRF = 2 × body weight
C. GRF = ½ body weight
D. None of the above
Answer: B
What type of energy is strain energy?
What type of energy is strain energy?
A. potential
B. kinetic
C. caloric
D. entropic
Answer: A
Which of the following factors does not affect the amount of friction generated between two dry surfaces?
Which of the following factors does not affect the amount of friction generated between two dry surfaces?
A. the coefficient of friction between the two surfaces
B. the surface area in contact
C. the reaction force
D. the normal force
Answer: B
Which of the following statements is true about the relationship between impact and impulse?
Which of the following statements is true about the relationship between impact and impulse?
A. impact is always greater than impulse
B. impulse is always greater than impact
C. impacts generate impulses
D. impulses generate impacts
Answer: C
Which of the following statements is true of the amount of horizontal force required to start an object sitting on a horizontal surface in motion?
Which of the following statements is true of the amount of horizontal force required to start an object sitting on a horizontal surface in motion?
A. it must be greater than the coefficient of kinetic friction
B. it must be greater than the coefficient of static friction
C. it must be greater than the maximum static friction force
D. it must be greater than the maximum kinetic friction force
Answer: C
When two bodies collide head-on and then continue to travel collectively in the original direction of motion of one of the bodies, what factor determines the direction of collective motion after the collision?
When two bodies collide head-on and then continue to travel collectively in the original direction of motion of one of the bodies, what factor determines the direction of collective motion after the collision?
A. the relative momenta of the two bodies
B. the relative masses of the two bodies
C. the relative acceleration of the two bodies
D. the relative weights of the two bodies
Answer: A
Which of the following is a correct unit of mechanical energy?
Which of the following is a correct unit of mechanical energy?
A. Joules
B. Watts
C. kg-m
D. kg/m
Answer: A
Which of the following pairs of quantities are expressed in the same units of measure?
Which of the following pairs of quantities are expressed in the same units of measure?
A. friction and weight
B. work and energy
C. both A and B
D. neither A nor B
Answer: C
Which of the following mechanical quantities is evident in explosive track and field events, such as the long jump and the shot put.
Which of the following mechanical quantities is evident in explosive track and field events, such as the long jump and the shot put.
A. kinetic energy
B. potential energy
C. mechanical work
D. mechanical power
Answer: D
Energy of motion is also called what?
Energy of motion is also called what?
A. potential energy
B. kinetic energy
C. strain energy
D. elastic energy
Answer: B
The capacity for doing work that a body possesses because of its height or position is called what?
The capacity for doing work that a body possesses because of its height or position is called what?
A. potential energy
B. kinetic energy
C. moment of inertia
D. mechanical power
Answer: A
The product of a force and the time during which it acts defines what?
The product of a force and the time during which it acts defines what?
A. momentum
B. velocity
C. acceleration
D. impulse
Answer: D
Which of the following is true of the coefficient of restitution of a racquetball?
Which of the following is true of the coefficient of restitution of a racquetball?
A. it depends solely on the type of material of which the ball is made
B. it depends on the size of the ball as well as the type of material
C. it depends solely on how hard the ball is hit
D. it is a number relating to the elasticity of a ball against a particular surface
Answer: D
Which of the following correctly describes impact?
Which of the following correctly describes impact?
A. large force applied over a long period of time
B. large force applied over a short period of time
C. small force applied over a long period of time
D. small force applied over a short period of time
Answer: B
Which of the following mechanical quantities is not dependent on time?
Which of the following mechanical quantities is not dependent on time?
A. work
B. power
C. kinetic energy
D. velocity
Answer: A
The principle of conservation of momentum restates which of Newton's laws?
The principle of conservation of momentum restates which of Newton's laws?
A. inertia
B. acceleration
C. action/reaction
D. gravitation
Answer: A
What variable may be described as "the quantity of motion" possessed by an object?
What variable may be described as "the quantity of motion" possessed by an object?
A. force
B. inertia
C. momentum
D. velocity
Answer: C
In sporting activities, what amount of friction is desired?
In sporting activities, what amount of friction is desired?
A. large
B. small
C. none
D. depends on the situation
Answer: D
The 2 variables that determine momentum are
The 2 variables that determine momentum are
A. velocity and time
B. velocity and mass
C. mass and acceleration
D. velocity and acceleration
Answer: B
Which quantity is not a force?
Which quantity is not a force?
A. friction
B. mass
C. weight
D. gravity
Answer: B
The higher the jump, the "harder" the landing. This statement reflects which of the following laws?
The higher the jump, the "harder" the landing. This statement reflects which of the following laws?
A. the law of inertia
B. the law of momentum
C. the law of torque
D. the law of action-reaction
Answer: D
A 500N gymnast performing a giant swing with an angular velocity of 5 rad/sec, exerts 90 Nm of torque on the support bar. How much torque is exerted by the bar on the gymnast's hands?
A 500N gymnast performing a giant swing with an angular velocity of 5 rad/sec, exerts 90 Nm of torque on the support bar. How much torque is exerted by the bar on the gymnast's hands?
A. 100 Nm
B. 2500 Nm
C. 590 Nm
D. 90 Nm
Answer: D
A skater gliding on ice will continue to move in the same direction and with the same speed (in the absence of the action of additional forces). This exemplifies which of the following laws?
A skater gliding on ice will continue to move in the same direction and with the same speed (in the absence of the action of additional forces). This exemplifies which of the following laws?
A. Newton's first law of inertia
B. Newton's second law of acceleration
C. Newton's third law of action/reaction
D. Newton's law of gravitational force
Answer: A
If an object of constant mass travels with a constant velocity, which statement is true?
If an object of constant mass travels with a constant velocity, which statement is true?
A. momentum is constant
B. acceleration is 0
C. both A and B
D. none of the above
Answer: C
What determines the time a horizontally projected object remains in the air?
What determines the time a horizontally projected object remains in the air?
A. weight
B. mass
C. projection height
D. all of the above
Answer: C
Which of the following relationships is correct?
Which of the following relationships is correct?
A. m = F/a
B. F = m/a
C. a = m/F
D. none of the above
Answer: A
Which of the following quantities would be different on the moon than on the earth?
Which of the following quantities would be different on the moon than on the earth?
A. acceleration due to gravity
B. mass
C. both mass and acceleration
D. neither mass nor acceleration
Answer: A
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