Physics [1 Mark Question Answer]

If the mass of the body m remains constant then the change in momentum of the body depends only on the change in its velocity.

Force is equal to the rate of change of momentum.

The momentum of a body is the product of the mass of the body and its velocity, i.e. p = mv.

When a force acts on a rigid body which is free to move, the body starts moving in a straight line in the direction of the force. This is called translational motion.

When a particle moves with a constant speed in a circular path, its motion is said to be the uniform circular motion.

Moment of force depends on two factors:
(i) Magnitude of force applied.
(ii) Distance of line of action of the force from the axis of rotation.

No.

Ideal machine has 100% efficiency i.e., work done on the machine = work done by the machine.

Non-contact force decreases with the increase in separation.

Force required for uniform circular motion is the centripetal force. It is directed towards its centre i.e., the centre of the circle.

When the number of teeth in driven gear is more than the number of teeth in driving gear.

When the number of teeth in a driving wheel is more than a number of teeth in a driven wheel.

The magnitude of a non-contact force depends on distance. If the magnitude of a non-contact force increasing then distance decreasing.

The work done by the coolie is zero because there is no displacement of’ the load in the direction of force, which he is applying vertically upwards.

Centre of gravity of a triangular lamina is situated at the point of intersection of its medians

Centre of the lamina

Drawing current from an electric cell.

Electric heater while in use.

Throwing up a pebble from the ground.

Rubbing of palms.

When electrolysis is carried out, the electric energy changes to potential energy.

The potential energy of stored water in dams, changes to electric energy in generators.

In an electric generator, the mechanical energy changes to electric energy.

In an electric motor, electric energy changes to mechanical energy.

During the burning of magnesium, chemical energy changes to light energy.

During photosynthesis, light energy changes to chemical energy.

When a loudspeaker works, the electric energy changes to sound energy.

When we speak in front of the microphone, sound energy changes to electric energy.

When two stones are rubbed against each other, kinetic energy changes to heat energy.

In the automobile engine, heat energy changes to kinetic energy.

Electric to heat energy to light energy.

The Kinetic energy changes into electricity.

The Kinetic energy changes into electricity.

Heat energy from the sun is converted into electricity.

The heat energy changes into electricity.

The electrical energy changes into heat energy and light energy.

Chemical energy to mechanical energy.

The chemical energy changes into heat energy.

The electrical energy changes to chemical energy.

The chemical energy changes into heat energy.

The light energy changes to chemical energy

The kinetic energy of water molecules is released in the form of heat energy.

During the burning of magnesium, chemical energy changes to heat and light energy.

The kinetic energy of moving car changes to potential energy.

The chemical energy of cell changes to electric energy. The electric energy first changes to heat and finally to light energy.

The heat energy changes to mechanical energy.

The kinetic energy changes to potential energy.

The potential energy changes to kinetic energy.

Electric energy to sound.