A 4kg package is released from rest at point A and slides down a frictionless track until it reaches point B with a speed of 4.20 m/s. From point B it slides on a level surface with friction coefficient a distance of 3.00 m to point C, where it comes to rest. Calculate the height H Calculate the coefficient of kinetic friction on the horizontal surface.

Explanation:

(a)   According to the law of conservation of energy,

               Potential energy = Kinetic energy

                     mgh =

Putting the given values into the above formula as follows.

               mgh =

                    h = 0.9 m

Therefore, the height H is 0.9 m.

(b)   For the given situation,

             Kinetic energy = work done by friction

                   u = 0.3

Thus, we can conclude that the coefficient of kinetic friction on the horizontal surface is 0.3.

in physics zero. in muscle fatigue could be high

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle