Pakistan MCQs

Centripetal acceleration changes the direction of velocity.
It always points radially inward.

Centripetal force is not a separate force type.
It may be supplied by tension, friction, gravity, or another force.

A particle in translational equilibrium has no acceleration.
It may be at rest or moving at constant velocity.

In ideal free fall, air resistance is neglected.
All objects then have the same gravitational acceleration locally.

Average speed equals distance divided by time.
120/10 = 12 m/s.

Displacement is 14-2 = 12 m.
Average velocity is 12/4 = 3 m/s.

The first law describes inertia.
A net external force is required to change velocity.

For constant mass, Newton's second law becomes F=ma.
It links net force to acceleration.

Interaction forces occur in pairs on different bodies.
They are equal in magnitude and opposite in direction.

Weight depends on gravitational field strength.
Mass remains constant while weight may change with location.

A surface exerts a normal force on an object in contact with it.
Its magnitude is not always equal to weight.

Friction acts tangentially at a contact surface.
It may be static or kinetic.