Answer:
Explanation:
Work Done (W):
The work done to lift the books is equal to the gravitational potential energy gained. We can calculate it using the formula: [ W = mgh ] where:
(m) is the mass (which we can find from the weight, as (F = mg))
(g) is the acceleration due to gravity (approximately (9.81 , \text{m/s}^2))
(h) is the height (given as 7 meters)
Plugging in the values: [ W = (10 , \text{N}) \cdot (7 , \text{m}) = 70 , \text{Joules} ]
Power (P):
Power is the rate at which work is done. It’s given by: [ P = \frac{W}{t} ] where:
(W) is the work done (which we calculated as 70 J)
(t) is the time taken (given as 50 seconds)
Plugging in the values: [ P = \frac{70 , \text{J}}{50 , \text{s}} = 1.4 , \text{watts} ]