Question

You apply a constant force F⃗ =(−68.0N)i^+(36.0N)j^ to a 420 kg car as the car travels 51.0 m in a direction that is 240.0∘ counterclockwise from the +x-axis.
How much work does the force you apply do on the car?

Answer 1

Answer:

Explanation:

The force magnitude is √(68.0² + 36.0²) = 76.9 N

force acts in direction

θ = arctan(36.0/-68.0) = 152.1°

The difference in angles is

240.0 - 152.1 = 87.9°  (nearly perpendicular)

The portion of the force acting in the direction of motion is

76.9cos87.9 = 2.82 N

Work done on the car is

W = Fd = 2.82(51.0) = 144 J