Biomechanics 12

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

90 Nm

The principle of conservation of momentum restates which of Newton's laws? A.inertia B.acceleration C.action/reaction D.gravitation

inerta

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

superball dropped on a hard surface

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

both A and B

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

A. acceleration due to gravity

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

A.Newton's first law of inertia

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

A:force and displacement

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

B:net torque and angular motion are in different directions

Which of the following would be typical for vertical ground reaction force (GRF) during running? A.GRF = body weight B.GRF = 2 X body weight C.GRF = ½ body weight D.None of the above

GRF = 2 X body weight

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

all of the above

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

all of the above

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

both A and B 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.

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 & B D.none of the above

both A and B are true

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

changes R

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

changes μs

In sporting activities, what amount of friction is desired? A.large B.small C.none D.depends on the situation

depends

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

impacts generate impulse

The product of a force and the time during which it acts defines what? A.momentum B.velocity C.acceleration D.impulse

impulse

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

it is a number relating to the elasticity of a ball against a particular surface

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

it must be greater than the maximum static friction force

Which of the following is a correct unit of mechanical energy? A.Joules B.Watts C.kg-m D.kg/m

joules

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

kg•m/s

Energy of motion is also called what? A.potential energy B.kinetic energy C.strain energy D.elastic energy

kinetic energy

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

large force over small time interval

Which of the following relationships is correct? A.m = F / a B.F = m / a C.a = m / F D.none of the above

m=F/a

Which quantity is not a force? A.friction B.mass C.weight D.gravity

mass

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

mechanical power

What variable may be described as "the quantity of motion" possessed by an object? A.force B.inertia C.momentum D.velocity

momentum

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

momentum is changed

What type of energy is strain energy? A.potential B.kinetic C.caloric D.entropic

potential

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

potential energy

What determines the time a horizontally projected object remains in the air? A.weight B.mass C.projection height D.all of the above

projection height

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

the law of action/reaction

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

the relative momenta of the two bodies

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

the surface area in contact

What is/are the direction(s) for vertical ground reaction force? A.up B.down C.sideways D.all of the above are possible directions

up

The 2 variables that determine momentum are A.velocity and time B.velocity and mass C.mass and acceleration D.velocity and acceleration

velocity and mass

Which of the following is a correct unit of mechanical power? A.Joules B.Watts C.kg-m D.kg/m

watts

Which of the following mechanical quantities is not dependent on time? A.work B.power C.kinetic energy D.velocity

work

Which of the following ? relationships is always true? A.μk < μs B.μs < μk C.μk = μs D.none of the above

μk < μs