Work and Energy...

When an object starts to fall freely, which statement is incorrect about it?
(A) Its potential energy is increased and kinetic energy is decreased
(B) Its kinetic energy is increased and potential energy is decreased
(C) Potential energy remains unchanged
(D) Kinetic energy remains unchanged

An object is falling from a height h, when it has fallen a height h/2, it will possess
A Half kinetic energy
B Half potential energy
C Only kinetic energy
D Only potential energy

Our hands become warm when rubbed against each other. This is because

The head of a nail hammered into the wooden plank becomes hot. This is because of

“Lever transforms mechanical energy into muscular energy” the above statement is

According to the law of conservation of energy

A ball is dropped from a height ‘h’. The velocity of the ball when it reaches the ground is 10 m/s. Find ‘h’. (g = 10ms⁻²)

Statement A: Mechanical energy of a system is always conserved.
Statement B: The total energy of the system is always conserved.
Which of the two statements is true?

Match the following with correct response.
(1) Battery
(2) Bulb
(3) Steam engine
(4) Microphone

(A) Electrical energy converts into light energy
(B) Sound energy converts into electrical energy
(C) Steam energy converts into mechanical energy
(D) Chemical energy converts into electrical energy

Work done by the gravitational force of earth on a satellite along a circular path is