What is the minimum power required for a conveyor to raise an 8.0 N box 4.0 m vertically in 8.0 s ?
260 W
32 W
4.0 W
64 W
Which is a unit of power ?
joule
joule/second
kilogram*meter/second
newton*meter2/second
A force of 10. N is required to keep an object moving at a constant speed of 5 m/s. The power used is
0.5 W
2 W
50
5 W
What is the maximum distance that a 60. W motor may vertically lift a 90. N weight in 7.5 s ?
2.3 m
5.0 m
140 m
1100 m
A weightlifter lifts a 2000 N weight a vertical distance of 0.5 m in 0.1 s. What is the power output ?
0.0001 W
0.0004 W
10,000 W
40,000 W
Which term is a unit of power?
Joule
Newton
Watt
Newton*meter
As the power of a machine is increased, the time required to move an object a fixed distance
increases
decreases
increases then decreases
remains the same
A force of 70 N must be exerted to keep a car moving with a constant speed of 10 m/s. What is the rate at which energy must be supplied ?
0.14 W
7.0 W
700 W
7000 W
A 3.0-kg block is initially at rest on a frictionless, horizontal surface. The block is moved 8.0 m in 2.0 sec by the application of a 12 N horizontal force. What is the average power developed while moving the block?
24 W
48 W
32 W
96 W
A 40.-kilogram student runs up a staircase to a floor that is 5.0 meters higher than her starting point in 7.0 seconds. The student's power output is