Physics Quiz 1-7 MC

A mass M is attached to an ideal massless spring. When this system is set in motion with amplitude A, it has a period T. What is the period if the amplitude of the motion is increased to 2A?

T

If we double only the amplitude of a vibrating ideal mass-and-spring system, the mechanical energy of the system

does not change

As you are leaving a building, the door opens outward. If the hinges on the door are on your right, what is the direction of the angular velocity of the door as you open it?

down

In simple harmonic motion, the speed is greatest at that point in the cycle when

the magnitude of the acceleration is a minimum

If the torque adds up to zero

the object could be accelerating linearly but it could not be turning

The components of vector A are Ax = +1.90 and Ay = -4.00. What is the angle measured counterclockwise from the +x axis to vector A?

295

A factory conveyer belt rolls at 3 m/s. A mouse sees a piece of cheese directly across from the belt and heads straight for the cheese at 4 m/s. What is the mouse's speed relative to the factory floor?

5 m/s

A person jumps out of an airplane above the surface of the Earth, and falls a distance h. The change in gravitational potential energy of the person+Earth system is A) negative B) positive C) zero D) insufficient information to answer

A) negative

An object is executing simple harmonic motion. What is true about the acceleration of this object? (There may be more than one correct choice) A) the acceleration is a maximum when the object is instantaneously at rest B) the acceleration is a maximum when the displacement of the object is a maximum C) the acceleration is a maximum when the speed of the object is a maximum D) the acceleration is a maximum when the displacement of the object is zero E) the acceleration is zero when the speed of the object is a maximum

A, B, and E

A ball is thrown directly upward and experiences no air resistance. Which of the following statements about its motion is correct? A) The acceleration of the ball is downward while it is traveling up and upward while it is traveling down B) The acceleration is downward during the entire time the ball is in the air C) The acceleration of the ball is upward while it is traveling up and downward while it is traveling down D) The acceleration of the ball is downward while it is traveling up and downward while it is traveling down but is zero at the highest point when the ball stops

B) The acceleration is downward during the entire time the ball is in the air

For general projectile motion, when the projectile is at the highest point of its trajectory A) its acceleration is zero B) its velocity is perpendicular to the acceleration C) its velocity and acceleration are both zero D) the horizontal component of its velocity is zero E) the horizontal and vertical components of its velocity is zero

B) its velocity is perpendicular to the acceleration

A box of mass m is pressed against (but is not attached to) an ideal spring of force constant k and negligible mass, compressing the spring a distance x. After it is released, the box slides up a frictionless incline and eventually stops. If we repeat this experiment but instead compress the spring a distance of 2x A) the box will go up the incline twice as high as before B) just as it moves free of the spring, the box will be traveling twice as fast as before C) just as it moves free of the spring, the box will be traveling four times as fast as before D) just as it moves free of the spring, the box will have twice as much kinetic energy as before E) just before it is release, the box has twice as much elastic potential energy as before

B) just as it moves free of the spring, the box will be traveling twice as fast as before

the fan blade is slowing down. What are the signs of omega and alpha? A) omega is positive and alpha is positive B) omega is positive and alpha is negative C) omega is negative and alpha is positive D) omega is negative and alpha is negative

B) omega is positive and alpha is negative

A person jumps out of an airplane above the surface of the Earth, and falls a distance h. The work done on the person by Earth is A) negative B) positive C) zero D) insufficient information to answer

B) positive

A 3.00-kg rifle fires a 0.00500-kg bullet at a speed of 300 m/s. Which force is greater in magnitude: the force that the rifle exerts on the bullet or the force that the bullet exerts on the rifle?

Both forces the same magnitude

A 645N student standing on a scale in an elevator notices that the scale reads 615N. From this information the students knows that the elevator must be moving A) upward B) downward C) you cannot tell if it is moving upward or downward

C) you cannot tell if it is moving upward or downward

A mosquito runs head-on into a truck. Splat! Which is true during the collision? A) The mosquito exerts more force on the truck than the truck exerts on the mosquito. B) The truck exerts more force on the mosquito than the mosquito exerts on the truck C) The mosquito exerts a force on the truck but the truck does not exert a force on the mosquito. D) The truck exerts a force on the mosquito but the mosquito does not exert a force on the truck E) The mosquito exerts the same force on the truck as the truck exerts on the mosquito`

E) The mosquito exerts the same force on the truck as the truck exerts on the mosquito

(T/F) A frictionless pendulum released from 65 degrees with the vertical will vibrate with the same frequency as if it were released from 5 degrees with the vertical because the period is independent of the amplitude and mass

False

Consider a uniform solid sphere of radius R and mass M rolling without slipping. Which form of its kinetic energy is larger, translational or rotational?

Its translational kinetic energy is larger than its rotational

An incompressible fluid flows steadily through a pipe that has a change in diameter. The radius at point P is 2R and the radius at point Q is R. Compare the pressure at point Q to point P

Point Q has smaller pressure

A heavy lead block and light aluminum block of equal sizes are both submerged in water. Upon which is the buoyant force greater?

They both experience the same buoyant force

Alice and Tom dive from an overhang into the lake below. Tom simply drops straight down from the edge, but Alice takes a running start and jumps with an initial horizontal velocity of 25 m/s. Neither person experiences any significant air resistance. Compare the time it takes each of them to reach the lake below.

They reach the surface of the lake at the same time

A pilot drops a package from a plane flying horizontally at a constant speed. Neglecting air resistance, when the package hits the ground the horizontal location of the plane will

be over the package

An incompressible fluid flows steadily through a pipe that has a change in diameter. The radius at point P is 2R and the radius at point Q is R. Compared to the fluid at point P, how does the flowrate at point Q differ.

it has the same volume flowrate

Two men, Joel and Jerry, push against a wall. Jerry stops after 10 min, while Joel is able to push for 5.0 min longer. Compare the work they do.

neither of them does any work

An incompressible fluid flows steadily through a pipe that has a change in diameter. The radius at point P is 2R and the radius at point Q is R. Compare the fluid speed at point Q to point P

point Q has 4 times the fluid speed

A solid sphere, solid cylinder, and a hollow pipe all have equal masses and radii and are of uniform density. If the three are released simultaneously at the top of an inclined plane and roll without slipping, which one will reach the bottom first?

solid sphere

Tensile stress is

the applied force per cross-sectional area

Two objects, one of mass m and the other of mass 2m, are dropped from the top of a building. When they hit the ground

the heavier one will have twice the kinetic energy of the lighter one

Two objects with different masses collide with and stick to each other. Compared to before the collision, the system of two objects after the collision has

the same amount of total momentum but less total kinetic energy

A sled moves on essentially frictionless ice. It is attached by a rope to a vertical post set in the ice. Once given a push, the sled moves around the post at a constant speed in a circle of radius R. If the rope breaks,

the sled will move in a straight line

A ball is tossed directly upward. When it reaches its highest point (before falling back down)

the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward

Two iceboats (one of mass m, one of mass 2m) hold a race on a frictionless, horizontal, frozen lake. Both iceboats start at rest, and the wind exerts the same constant force on both iceboats. Which iceboat crosses the finish line with more kinetic energy.

they both cross the finish line with the same kinetic energy

A stalled car is being pushed up a hill at a constant velocity by three people. The net force on the car is

zero