Work and Power Answers

8 verified answers2 views
1
Free Preview

Trevor is pulling his younger brother in a wagon. He pulls the wagon 50 m to the corner with a force that is parallel with the ground. He then turns the wagon around and pulls it 50 m back to the starting point with the same force at an angle of 30° with respect to the ground.

A
They are the same because he uses the same amount of force.
B
They are the same because he travels the same distance.
C
He does less work coming back because the force moving the wagon is only 50cos30°.
D
He does more work coming back because the force moving the wagon is only 50cos60°.
3

In which scenario is the least amount of work done on a crate?

A
A force of 120 N moves it 25 m.
B
A force of 115 N moves it 26 m.
C
A force of 130 N moves it 22 m.
D
A force of 125 N moves it 27 m.
4

How do the units of work and power compare?

A
The unit for work is a watt. The unit for power is a joule, which is a watt-second.
B
The unit for work is a watt. The unit for power is a joule, which is a watt per second.
C
The unit for work is a joule. The unit for power is a watt, which is a joule-second.
D
The unit for work is a joule. The unit for power is a watt, which is a joule per second.
6

What is the unit for work?

A
watt
B
joule
C
newton
D
meter
8

Hiro walks up a flight of stairs in his apartment building. Later in the day, he runs up the same flight of stairs.

A
He did more work running than walking.
B
He did more work walking than running.
C
He had more power running than walking.
D
He had more power walking than running.
9

A force of 75 N at an angle of 15° to the direction of motion moves a chair 3 m. Which change would result in more work being done on the chair?

A
using 60 N of force
B
moving the chair 2 m
C
increasing the angle to 20°
D
decreasing the angle to 10°

Did you find these answers helpful?