Sure !
The work is (weight of the book) x (height of the desk above the floor).
The force (weight) is the result of gravity.
It was gravity that did the work.
Answer:
Reverse check the answer
Explanation:
I believe it is very important that once someone is done with any calculation, the person ought to go over the calculations again. And even, recheck the answer in inverted form.
This is so because while doing the calculations, we can possibly make errors that we won't notice until after submission. Knowing 2 * 3 = 6, but writing 2 * 3 = 5 in the course of calculations can happen to anybody. So therefore, cross checking and reverse checking is needed
Answer:
Centripetal force is equal to 31.55 N
Explanation:
We have given mass of the body m = 8 kg
Radius of the circular path r = 10 m
It is given that it makes 1 revolution in 10 seconds
Distance traveled in 10 seconds is equal to 
Velocity is equal to 
We have to find the centripetal force
Centripetal force is equal to 
So centripetal force will be equal to 31.55 N
Since it is restricted at both ends, λ/2 = length of string
λ/2 = 1.5m
λ = 1.5*2 = 3m
