Answer:
P = 2,000 W
Explanation:
Work and Power
Work is the amount of energy transferred by a force over a distance. It's a scalar quantity, with SI units of joules.
If both the force F and displacement s are parallel, then we can use the equivalent scalar formula:
W=F.s
Power is the amount of energy transferred or converted per unit of time. In the SI, the unit of power is the watt, equal to one joule per second.
The power can be calculated as:
[tex]\displaystyle P=\frac {W}{t}[/tex]
Where W is the work and t is the time.
A box with a weight of 1,000N is lifted by s=20 m by a rope and pulley system. The system exerts a force equal to the weight of the box, thus F=1,000 N. The work done by the system is:
W =1,000 N * 20 m
W = 20,000 J
Now we calculate the power developed by the system in t=10 seconds:
[tex]\displaystyle P=\frac {20,000}{10}[/tex]
P = 2,000 W
