### A job is done slowly, while an identical job is done quickly. Both jobs require the same amount of work, but different amounts of

power

### What task requires the most work: lifting a 50 kg sack 2 meters or lifting a 25 kg sack 4 meters?

both require the same amount of work

### It takes 40 J to push a large box 4 m across a floor. Assuming the push is in the same direction as the move, what is the force acting on the box?

10 N

### A 2 kg mass is held 4 m above the ground. What is the approximate potential energy of the mass with respect to the ground?

80 J

### A 2 kg mass has 40 J of potential energy with respect to the ground. Approximately how high above the ground is it?

2 m

### Using 100 J of work, a toy elevator is raised from the ground floor to the second floor in 20 seconds. The power needed to do this job was

50 W

### Two identical arrows, one with twice the kinetic energy of the other, and are fired into a hay bale. The faster arrow will penetrate

twice as far as the slower arrow

### A car moves 4 times as fast as another identical car. Compared to the slower car the faster car has

16 times the KE

### A ball is projected into the air with 100 J of kinetic energy which is transformed to gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is

100 J or less than 100 J

### Strictly speaking, more fuel is consumed by your car if an air conditioner, headlights, or even a radio is turned on. This statement is

almost always true

### A woman carries a heavy box across a room at a constant speed. How much work does she do on the box while walking?

none

### Which has greater kinetic energy, a car traveling at 30 km/h or a car of half the mass traveling at 60 km/h?

the 60 km/h car

### If a ping pong ball and a golf ball are both moving in the same direction with the same amount of kinetic energy, the speed of the ping pong ball must be

the same as the golf call

### The index of refraction for water is 1.33 while the index of refraction for ether is 1.47. Light will travel faster in the

water

### If a beam of light were to go from either into water, which of the following would be true?

the light beam would bend away from the normal

### When light passes from a medium with a high index of refraction to a medium with a low index of refraction it will bend

away from the normal

### When light passes from a more optically dense medium into a less optically dense medium it will bend

away from the normal

### the period of the wave is defined as the time it takes for one complete cycle of a wave to occur

true

### The vibrations of a transverse wave move in a direction

at right angles to the directions of wave travel

### A 60-vibration-per-second wave travels 30 meters in 1 second. Its frequency is

60 Hz and it travels at 30 m/s

### A weight suspended from a spring bobs up and down over a distance of 1 meter in two seconds. Its frequency is

waves test #17

### You dip your finger repeatedly into water and make waves. If you dip your finger more frequently, the wavelength of the waves

shortens

### As a train of water waves goes by, a piece of cork floating on the water bobs up and down one complete cycle each second. The waves are 2 meters long. What is the speed of the wave?

2 m/s

### A skipper on a boat notices wave crests passing the anchor chain every 5 seconds. The skipper estimates the distance between the crest is 15 m. What is the speed of the water waves?

3 m/s