PPSC MCQs

Friction resists sliding or rolling between surfaces.
It can produce heat and slow moving objects.

Grooves help tyres maintain contact with the road.
They also channel water away and reduce skidding.

Oil forms a lubricating layer between moving surfaces.
This reduces friction, wear, and overheating.

Inertia causes an object to remain at rest or in uniform motion unless acted on.
Greater mass generally means greater inertia.

Their bodies tend to continue moving forward when the bus stops.
This is an example of inertia of motion.

Newton's third law describes paired interaction forces.
Each force is matched by an equal force in the opposite direction.

The rocket pushes exhaust gases downward.
The gases exert an equal and opposite force on the rocket.

The joule is the SI unit of work and energy.
It equals the work done by a force of one newton over one metre.

Power is the rate of doing work or using energy.
Its SI unit is the watt.

Speed equals distance divided by time.
It describes how quickly an object moves.

Average speed is total distance divided by total time.
Thus, 120 ÷ 2 = 60 km/h.

Gravity attracts masses toward one another.
Near Earth, it pulls objects toward the ground.