ScalarVector & Estimating
Which pair of quantities represent scalar quantities? (1) displacement and velocity
(2) displacement and time
(3) energy and velocity
(4) energy and time
(4) Energy and Time
A 12.0-kilogram cart is moving at a speed of 0.25 meter per second. After the speed of the cart is tripled, the inertia of the cart will be
(1) unchanged
(2) one-third as great
(3) three times greater
(4) nine times greater
(1) unchanged
How would the mass and weight of an object on the Moon compare to the mass and weight of the same object on Earth?
(1) Mass and weight would both be less on the Moon.
(2) Mass would be the same but its weight would be less on the Moon.
(3) Mass would be less on the Moon and its weight would be the same.
(4) Mass and weight would both be the same on the Moon.
(2) Mass would be the same but its weight would be less on the Moon.
An air bag is used to safely decrease the momentum of a driver in a car accident. The air bag reduces the magnitude of the force acting on the driver by
(1) increasing the length of time the force acts on the driver
(2) decreasing the distance over which the force acts on the driver
(3) increasing the rate of acceleration of the driver
(4) decreasing the mass of the driver
(1) increasing the length of time the force acts on the driver
In what direction does centripetal force act?
To the center
Which combination correctly pairs a vector quantity with its corresponding unit?
(1) weight and kg
(2) velocity and m/s
(3) speed and m/s
(4) acceleration and m2/s
(2) velocity and m/s
A hiker travels 1.0 kilometer south, turns and travels 3.0 kilometers west, and then turns and travels 3.0 kilometers north. What is the total distance traveled by the hiker?
7 km
A tennis player’s racket applies an average force of 200. newtons to a tennis ball for 0.025 second. The average force exerted on the racket by the tennis ball is
200N
A blue lab cart is traveling west on a track when it collides with and sticks to a red lab cart traveling east. The magnitude of the momentum of the blue cart before the collision is 2.0 kilogram • meters per second, and the magnitude of the momentum of the red cart before the collision is 3.0 kilogram • meters per second. The magnitude of the total momentum of the two carts after the collision is
1 kg-m/s
A 2.0 × 103 -kilogram car travels at a constant speed of 12 meters per second around a circular curve of radius 30. meters. What is the magnitude of the centripetal acceleration of the car as it goes around the curve?
4.8 m/s2
Which measurement is closest to 1 × 10−2 meter?
(1) diameter of an atom
(2) width of a student’s finger
(3) length of a football field
(4) height of a schoolteacher
(2) width of a student’s finger
A 6.0-kilogram cart initially traveling at 4.0 meters per second east accelerates uniformly at 0.50 meter per second squared east for 3.0 seconds. What is the speed of the cart at the end of this 3.0 second interval?
5.5 m/s
A 5.0-kilogram box is sliding across a level floor. The box is acted upon by a force of 27 newtons east and a frictional force of 17 newtons west. What is the magnitude of the acceleration of the box?
2m/s2
A 0.500-kilogram cart traveling to the right on a horizontal, frictionless surface at 2.20 meters per second collides head on with a 0.800-kilogram cart moving to the left at 1.10 meters per second. What is the magnitude of the total momentum of the two-cart system after the collision?
0.22 kg-m/s
An object is moving with constant speed in a circular path. The object’s centripetal acceleration remains constant in
(1) magnitude, only
(2) direction, only
(3) both magnitude and direction
(4) neither magnitude nor direction
(1) magnitude, only
The diameter of an automobile tire is closest to
(1) 10−2 m (3) 101 m
(2) 100 m (4) 102 m
(2) 100 m
Starting from rest, a car travels 18 meters as it accelerates uniformly for 3.0 seconds. What is the magnitude of the car’s acceleration?
4 m/s2
0 An object weighing 2.0 newtons is pushed across a horizontal, frictionless surface by a horizontal force of 4.0 newtons. What is the magnitude of the net force acting on the object?
4 N
A golf club hits a stationary 0.050-kilogram golf ball with an average force of 5.0 × 103 newtons, accelerating the ball to a speed of 44 meters per second. What is the magnitude of the impulse imparted to the ball by the golf club?
2.2 kg-m/s
Centripetal force Fc acts on a car going around a curve. If the speed of the car were twice as great, what happens to the magnitude of the centripetal force necessary to keep the car moving in the same path? Be specific
It quadruples
The height of a 30-story building is approximately
(1) 100 m (3) 102 m
(2) 101 m (4) 103 m
(3) 102 m
While taking off from an aircraft carrier, a jet starting from rest accelerates uniformly to a final speed of 40. meters per second on a runway that is 70. meters long. What is the magnitude of the acceleration of the jet?
11.4 m/s2
If a block is in equilibrium, the magnitude of the block’s acceleration is
(1) zero
(2) decreasing
(3) increasing
(4) constant, but not zero
(1) zero
A 1000.–kilogram car traveling 20.0 meters per second east experiences an impulse of 2000. newton • seconds west. What is the final velocity of the car after the impulse has been applied?
(1) 18.0 m/s east (3) 20.5 m/s west
(2) 19.5 m/s east (4) 22.0 m/s west
(1) 18.0 m/s east
A 1750-kilogram car travels at a constant speed of 15.0 meters per second around a horizontal, circular track with a radius of 45.0 meters. What is the magnitude of the centripetal force acting on the car?
8750N