Gravity
A book rests on a table. According to Newton's third law, the reaction force to the book's weight (gravitational pull of Earth on the book) is:
a) The normal force of the table pushing up on the book
b) The gravitational pull of the book on Earth
c) The friction force between the book and table
d) The weight of the table pushing down on the floor
B - b) The gravitational pull of the book on Earth
A hockey puck slides across frictionless ice at constant velocity. Which statement best describes the net force on the puck?
a) The net force equals the puck's weight
b) There is a forward force keeping it moving
c) The net force is zero
d) The net force decreases as the puck slows
c) The net force is zero
A ball is launched horizontally from a cliff. Which statement correctly describes its motion?
a) Horizontal velocity increases due to gravity
b) Vertical velocity remains constant throughout the fall
c) Horizontal and vertical motions are independent of each other
d) The ball follows a straight-line path downward
c) Horizontal and vertical motions are independent of each other
A roller coaster car starts from rest at the top of a hill and rolls down to the bottom (no friction). Which statement best describes the energy transformation?
a) Kinetic energy is created from nothing
b) Gravitational potential energy converts to kinetic energy
c) Kinetic energy converts to gravitational potential energy
d) Mechanical energy increases as the car descends
b) Gravitational potential energy converts to kinetic energy
An object moving in a circle at constant speed is accelerating because:
a) Its speed is increasing
b) The direction of its velocity is continuously changing
c) Gravity pulls it toward the center
d) Friction acts along the direction of motion
b) The direction of its velocity is continuously changing
Two objects, one with twice the mass of the other, experience the same net force. How do their accelerations compare?
a) The heavier object accelerates twice as fast
b) Both objects accelerate at the same rate
c) The lighter object accelerates twice as fast
d) The heavier object accelerates four times as fast
c) The lighter object accelerates twice as fast
A block is pushed across a horizontal surface at constant velocity. This means the applied force must be:
a) Greater than the friction force
b) Less than the friction force
c) Equal to the friction force
d) Equal to the weight of the block
c) Equal to the friction force
At the highest point of a projectile's trajectory (launched at an angle), which of the following is true?
a) Both horizontal and vertical velocity are zero
b) Only vertical velocity is zero; horizontal velocity remains
c) Only horizontal velocity is zero; vertical velocity remains
d) The acceleration of the projectile is zero
b) Only vertical velocity is zero; horizontal velocity remains
In the absence of friction and air resistance, the total mechanical energy of a falling object:
a) Increases as it falls
b) Decreases as it falls
c) Remains constant
d) Depends on the object's mass
c) Remains constant
The centripetal force on an object in circular motion always points:
a) Tangent to the circle in the direction of motion
b) Away from the center of the circle
c) Toward the center of the circle
d) Opposite to the direction of motion
c) Toward the center of the circle
Two identical balls are released simultaneously from the same height. Ball A is dropped straight down; Ball B is launched horizontally. Which hits the ground first?
a) Ball A, because it travels a shorter path
b) Ball B, because it has more initial velocity
c) They hit the ground at the same time
d) It depends on the horizontal speed of Ball B
c) They hit the ground at the same time
The normal force on a block resting on a frictionless inclined plane compared to a horizontal surface is:
a) Greater on the incline
b) Equal on both surfaces
c) Less on the incline
d) Zero on the incline
c) Less on the incline
If a velocity vector is resolved into horizontal and vertical components, which trigonometric functions are used to find those components from the angle above the horizontal?
a) Sine for horizontal, cosine for vertical
b) Cosine for horizontal, sine for vertical
c) Tangent for both components
d) Cosine for both components
b) Cosine for horizontal, sine for vertical
A large force acts on an object for a very short time. Compared to a smaller force acting for a longer time that produces the same impulse, the change in momentum of the object is:
a) Greater for the large force
b) Greater for the smaller force
c) The same for both
d) Zero for both
c) The same for both
If the speed of an object in circular motion doubles while the radius stays the same, the centripetal force required:
a) Doubles
b) Stays the same
c) Quadruples
d) Halves
c) Quadruples
If an object's height above the ground doubles, its gravitational potential energy:
a) Stays the same
b) Doubles
c) Quadruples
d) Halves
b) Doubles
A vector quantity differs from a scalar quantity in that a vector:
a) Has only magnitude
b) Can be negative
c) Has both magnitude and direction
d) Is always larger than a scalar
c) Has both magnitude and direction
A force of 30 N acts to the right and a force of 40 N acts upward on the same object. The magnitude of the resultant force is:
a) 10 N
b) 35 N
c) 50 N
d) 70 N
c) 50 N
Impulse is defined as:
a) The rate of change of velocity
b) Force multiplied by time
c) Mass multiplied by acceleration
d) The product of mass and displacement
Force multiplied by time
In a perfectly inelastic collision, the objects:
a) Bounce apart with no loss of kinetic energy
b) Stick together and move as one unit
c) Exchange velocities
d) Both come to a complete stop
b) Stick together and move as one unit
The gravitational force between two objects depends on:
a) Their masses and the distance between them
b) Their velocities and masses
c) Their volumes and the distance between them
d) Their temperatures and masses
a) Their masses and the distance between them
Which statement correctly compares static and kinetic friction?
a) Kinetic friction is always greater than static friction
b) Static friction can vary in magnitude up to a maximum value; kinetic friction is approximately constant
c) Static and kinetic friction are always equal
d) Kinetic friction acts before an object begins to move
b) Static friction can vary in magnitude up to a maximum value; kinetic friction is approximately constant
A player throws a ball up into the air and it returns to player. What is the speed of the ball when it returns the player's glove?
a) zero
b) less than when he threw it
c) equal to when he threw it
d) more than when he threw it
c) equal to when he threw it
Which quantity is conserved in ALL types of collisions (both elastic and inelastic)?
a) Kinetic energy
b) Velocity
c) Momentum
d) Mechanical energy
c) Momentum
a) the normal force is zero
b) the normal force is equal to the velocity
c) the normal force is equal to the gravitational force
d) the normal force is greater than the gravitational force.
a) the normal force is zero