PHYSICS HELP with parts. A boy flies a kite with the string at a 30∘ angle to the horizontal. The tension in the string is 4.5 N.?

Work is a force times the distance moved in the direction of that force

A)How much work does the string do on the boy if the boy stands still?

Zero (no distance moved)

B)How much work does the string do on the boy if the boy walks a horizontal distance of 11 m AWAY from the kite?

as the boy is assumed to be moving horizontally, only the horizontal force component can do work.

W = 4.5cos30(-11)

W = - 42.868...

W = -43 J

it is negative because the force vector and the motion vector are in opposite directions.

C)How much work does the string do on the boy if the boy walks a horizontal distance of 11 m TOWARD the kite?

W = 43 J

Same logic as in B but the motion and force are both in the same direction, so positive work.

The vertical component of the force does no work as there is no motion in the direction of that force.

I hope this helped.

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