Lesson: Conservation of Energy

A body of mass 20 kg fell from a height of 42.3 m above the surface of the ground. Find the sum of its kinetic energy and its potential energy relative to the ground 2 seconds after it started falling. Take .

A body of mass 7 kg fell vertically from point to the ground. Given that, when it reached the ground, its kinetic energy was 3 724 joules, find its gravitational potential energy relative to the ground when it was at point . Consider the acceleration due to gravity to be 9.8 m/s².

A body started to slide down a smooth inclined plane of height 504 cm from its top. Find its speed when it reached the bottom. Take .

A body of mass 55 g started sliding down a smooth inclined plane. Find the gravitational potential energy lost by the time the body’s speed reached 2 m/s.

A body of mass 9 kg fell vertically from a point 3.4 m above the ground. At a certain moment, the speed of the body was 3.9 m/s. Determine the change in the body’s gravitational potential energy from this point until it reached a point 68 cm above the ground. Take .