2. A rollerskate is dragged across the ground for 3.4 meters, by someone pulling on its shoelace. The shoelace makes a 15° angle with the horizontal, and the tension in the shoelace is 4.6N. What is the work done on the rollerskate by the shoelace? Be sure to include whether it is positive or negative. 15° 3.4m D

1. A 7.50-kg box initially at rest slides down a 15.0 m long incline that makes an angle of 22.0° with the horizontal (see figure). At the bottom of the incline, the speed of the box is 3.00 m/s. a) Draw a free body diagram, detailing all of the forces acting on the box. b) Using the work done by non-conservative forces relationship, find the algebraic expression for the coefficient of kinetic friction between the box and the incline. c) Calculate the coefficient of kinetic friction.

On a horizontal surface with µk = 0.70, a 5kg object is dragged with 350N force directed due East. a. Draw all forces, and calculate the work done by each force if the object moves from 3 m to 10 m on the x-axis. Calculate the total work.

In the Figure below, we see a 500 gram block resting on the horizontal portion of a "track", whose left end is curved upwards. The horizontal portion of the track is frictionless, except for a 50.0 cm long “rough" portion, shown in the Figure, where the coefficient of kinetic friction is 0.300. The curved portion of the track is frictionless. The block is held against a spring (which has a stiffness constant of 500 N/m), compressing the spring by 10.0 cm. Then the block is released from rest. (NOTE: The block is not attached to the spring; it is just held against the end of the spring.) For simplicity, assume that g = 9.80 m/2. 50.0 cm