A custodian pulls a vacuum 13.5 m with a 33.9 N force at a 55.0 degree angle , against a 14.2 N friction force . find the work done by the friction force

a. -191.7 J

Explanation:

The work done by a force is given by W = Fdcosθ where F = force applied and d = distance moved and θ is the angle between the force and distance moved.

Here, F = frictional force = 14.2 N

d = distance = 13.5 m

and θ = 180° since the direction of the frictional force and distance are opposite.

So, W = Fdcosθ = 14.2 × 13.5cos180° = -191.7 J

close lines strong magnet less close weaker

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west