Question

A mass m = 17 kg is pulled along a horizontal floor, with a coefficient of kinetic friction ?k = 0.06, for a distance d = 6.7 m. Then the mass is continued to be pulled up a frictionless incline that makes an angle ? = 33° with the horizontal. The entire time the massless rope used to pull the block is pulled parallel to the incline at an angle of ? = 33° (thus on the incline it is parallel to the surface) and has a tension T = 46 N.

What is the work done by tension before the block gets to the incline?

What is the work done by friction as the block slides on the flat horizontal surface?

What is the speed of the block right before it begins to travel up the incline?

How far up the incline does the block travel before coming to rest?

What is the work done by gravity as it comes to rest?

During the entire process, the net work done on the block is:

Answer 1

a) Work done by tension = T x d = 46 x 6.7 = 308.2 J

b)Work done by friction = uW x d = 0.06 x 17 x 9.81 x 6.7 = 67J

c) Net force in Block = Tension - Friction = 46 - 0.06 x 17 = 44.9 N

accleration = F/m = 44.9 / 17 = 2.64 m/s²

v = 6m/s

d) Net force when moving up the incline = T - Wsin 33 = 46 - 17 x 9.81 x sin 33 = -44.8 N

accleration = -44.8 / 17 = -2.63 m/s²

s = 6.8 m

After 6.8m in the incline the block will stop moving