# Power And Work Quiz

10 Questions | Total Attempts: 501  Settings  • 1.
The units of power are:
• A.

Watts

• B.

Joules

• C.

Newtons

• D.

Meters

• 2.
A constant force of 10 N causes a box to move at a constant speed of 2 m/s. How much power is done in 10 seconds?
• A.

200W

• B.

20W

• C.

2W

• D.

2000W

• 3.
Power is defined as:
• A.

Work per unit length (W/d)

• B.

Work times time (W∙t)

• C.

Force per unit length (F/d)

• D.

Work per unit time (W/t)

• 4.
How is work related to acceleration?
• A.

W = m∙a

• B.

W = m∙a∙t

• C.

W = m∙a∙d

• D.

W = m∙a/d

• 5.
In a period of 10 seconds, an elevator lifts a weight of 1000 N a distance of 10 m at constant velocity. What is the average power of the elevator over this time?
• A.

1000W

• B.

10000W

• C.

10W

• D.

100W

• 6.
Liz throws a softball with a force of 63 N a distance of 25 m. Jamie throws the softball with the twice amount of force, but the ball only goes 17 m. Which girl does less work?
• A.

Jamie

• B.

Liz

• C.

Both are the same

• D.

Option 4

• 7.
A machine using a power of 1000W requires a force of 100 N to raise a mass in 10 s. The height the mass is raised in this time is
• A.

10000m

• B.

1000m

• C.

10m

• D.

100m

• 8.
How much energy is needed to run a 75-watt light bulb for 6 seconds?
• A.

12.5J

• B.

100J

• C.

450J

• D.

5J

• 9.
A student is running up 3 flights of stairs. He runs up the first flight quickly but the last two he tires so goes a little slower. When does he exert more power and why?
• A.

The last flight because he is tired and trying more

• B.

The first flight because he takes less time

• C.

The second flight because he takes more time

• D.

The power is the same for all three flights of stairs

• 10.
An escalator is used to move 20 passengers every minute from the first floor of a department store to the second. The second floor is located 5.20 meters above the first floor. The average passenger's mass is 54.9 kg. Determine the POWER requirement of the escalator in order to move this number of passengers in one minute.
• A.

47 Watts

• B.

55954 Joules

• C.

2797 Joules

• D.

951.6 Watts

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