Aboy flies a kite with the string at a 30∘ angle to the horizontal. the tension in the string is 4.5 n. how much work does the string do on the boy if the boy stands still? how much work does the string do on the boy if the boy walks a horizontal distance of 11 m away from the kite? how much work does the string do on the boy if the boy walks a horizontal distance of 11 m toward the kite?

a) W = 0

b) W = -42.87 J

c) W = +42.87 J

Explanation:

As we know that work done is defined as

here F = applied force

d = displacement

Part a)

here the boy stands still to hold the string

so here displacement d = 0

so work done

W = 0 J

Part b)

Here boy run opposite to the direction of tension in string

so here work done is given as

Part c)

here boy run in the same direction in which tension is applied

so here work done is given as