A force of 75 N at an angle of 15° to the direction of motion moves a chair 3 m. Which change would result in more work being done on the chair? using 60 N of force moving the chair 2 m increasing the angle to 20° decreasing the angle to 10°

Question

Caitlin Warner

Physics

23 March, 03:27

A force of 75 N at an angle of 15° to the direction of motion moves a chair 3 m. Which change would result in more work being done on the chair? using 60 N of force moving the chair 2 m increasing the angle to 20° decreasing the angle to 10°

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Answers (1)

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Mcdonald · Answer 1

Decreasing the angle to 10°

Explanation:

(work) = (force in direction of motion) x (displacement)

The component of the force in the direction of the motion is

(force in direction of motion) = (magnitude of force 75N) x (cos 15 degrees) = 72.44 N

If we change the angle from 15 to 10 degrees the same will become

(75N) x (cos 10 degrees) = 73.87N

Given the displacement of 3m, the work is increased from (72.44N) x (3m) = 217.32 J, to (73.87N) x (3m) = 221.58 J

In other words, reducing the angle of (or, aligning) the force to the direction of motion, increases the work done on the chair.

As for the other choices:

* Using 60N of force will decrease the work.

* Moving the chair 2m will decrease the work done.

* Increasing the angle to 20 degrees will reduce the work done (opposite argument to the answer above)