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.?
Please help A boy flies a kite with the string at a 30∘ angle to the horizontal. The tension in the string is 4.5 N.
A)How much work does the string do on the boy if the boy stands still?
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?
C)How much work does the string do on the boy if the boy walks a horizontal distance of 11 m TOWARD the kite?
?2016-11-03T07:28:39Z
Favorite Answer
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. As a form of exchange, please remember to vote a "Best Answer" from among your results. This is not the same as "like" or "thumbs up" which are also nice and do boost points, but only if followed by asker awarding the Best Answer points with their vote.