Question

A) A massless rope is tied to a 1.82 kg box sitting on a rough, horizontal surface. The rope is pulled with constant force F acting upward at an angle 15.8^o to the horizontal. The coefficient of kinetic friction between the box and the surface is 0.217, and the box slides at constant speed along the table for a distance of 84.4 m. Find the total work done by F, in J.

B)Josh, mass 143 kg, is racing against his daughter Laura, and they have the same kinetic energy.  When Josh increases his speed by 69.6%, they are running at the same speed. Find Laura's mass, in kg.  

C)At t = 0, a 8.72 kg box is sliding across a rough, horizontal surface at speed 3.1 m/s. If the friction between the box and the table brings it to rest: find W, the work done by friction on the box.

D)A 2.6 kg box sliding at 10.7 m/s along a horizontal, frictionless surface comes to a rough incline that makes an angle of 41.7^o with the horizontal.  The box slides 8.5 m up along the surface of the incline, and comes to rest.  Find the work done by friction on the box, in J.

Answer 1

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