Pakistan MCQs

Work transfers energy when a force acts through a displacement.
Only the component of force along displacement contributes.

Moment of inertia depends on mass and its distribution about the axis.
Mass farther from the axis increases it.

Kinetic energy depends on mass and speed.
For translational motion, K=½mv².

A body in rotational equilibrium has no angular acceleration.
Clockwise and counterclockwise torques balance.

Near Earth's surface, gravitational potential energy is mgh.
Only changes in potential energy are physically significant.

Work is W=Fd when force and displacement are parallel.
W=20×5 = 100 J.

Power measures how quickly work is done.
Its SI unit is the watt.

The net work on an object changes its kinetic energy.
This relation is valid for the total work of all forces.

Conservative forces transfer energy between kinetic and potential forms.
Nonconservative work changes total mechanical energy.

Acceleration is net force divided by mass.
A=30/6 = 5 m/s².

Weight is W=mg.
W=7×10 = 70 N.

Vertical equilibrium requires normal force to balance weight.
N=mg=10×10 = 100 N.