Mechanics | Relativity Answers

A body of mass 10kg and initially at rest is subjected to force of 20N for 1s. Calculate the change in kinetic energy

An engine raises 100kg of water through a height of 60m in 20s. What is the power of the engine?
(g= 10m/s)

A 20kg body is allowed to roll do an inclined plane 4m long with an inclination 30 degree. Calculate the work done. (g=10m/s)

A boy whose mass is 40kg rams up a flight of 30 steps each. 150mm high, in 6s. Find the average power developed

If a force of 100N stretches a spring by 0.1cm, find
a) the elastic constant
b) the work done in stretching the spring 0.3cm if the elastic limit is not exceeded

A bullet of mass 0.045kg is fired from a gun of mass 9kg, it bullet moving with an initial velocity of 200m/s. Find the initial backward velocity of the gun.

A body of mass 2kg moving with velocity of 6m/s collides with a stationary object of mass 0.5kg. If the two bodies move together after the impact, calculate their common velocity

A cleaner pushes a 4.50-kg laundry cart in such a way that the net external force on it is 60.0N. Calculate its acceleration.

A 63.0kg sprinter starts a race with an acceleration of 4.20m/s square. What is the net external force on him?
If the sprinter from the previous problem accelerates at that rate for 20m, and then maintains that velocity for the remainder for the 100-m dash, what will be his time for the race?

A soccer player starts from rest and accelerates forward, reaching a velocity of 8.00m/s in 2.50s. a) What was his average acceleration? b) what average force did he exert backward on the ground to achieve this acceleration? The players mass is 70.0kg, and air resistance is negligible