A 10.0-kg microwave oven is pushed 8.00 m up the sloping surface of a loading ramp inclined at an angle of 36.9° above the horizontal, by a constant force with a magnitude 110 N and acting parallel to the ramp. The coefficient or kinetic friction between the oven and the ramp is 0.250. (a) What is the work done on the oven by the force ? (b) What is the work done on the oven by the friction force? (c) Compute the increase in potential energy for the oven. (d) Use your answers to parts (a), (b), and (c) co calculate the increase in the oven’s kinetic energy. (e) Use to calculate the acceleration of the oven. Assuming that the oven is initially at rest, use the acceleration to calculate the oven’s speed after traveling 8.00 m. From this, compute the increase in the oven’s kinetic energy, and compare it to the answer you got in part (d).
Solution 14E Step 1: Step 2: a) Work done on the oven by the force W = F.d F =110N d (displacement)= 8 W =110 ×8 W =880 b) the work done on the oven by the friction force Friction force Ff= N Ff= mgcos() Mass, m=10kg Acceleration due to gravity, g=908 Coefficient of friction = 0.250 Ff= 10×9.8×cos(36.9)× 0.250 Ff = 19.59N Work done by oven by friction Wf=Ff×dcos() The angle made in this case is 180degree Wf = 19.59×8 cos (36.9) Wf = 125.33N