Pakistan MCQs

Opposing forces subtract.
Net force = 50-20 = 30 N.

Use a=F/m.
A=12/4 = 3 m/s².

Centripetal force is mv²/r.
F=2×36/4 = 18 N.

Centripetal acceleration is v²/r.
A=100/20 = 5 m/s².

Acceleration is F/m = 4 m/s².
Change in velocity is at=4×3 = 12 m/s.

The net force is 80-20 = 60 N.
Acceleration is 60/15 = 4 m/s².

Use s=ut+½at².
S=10×5+½×2×25 = 50+25 = 75 m.

Use v²=u²+2as.
100-16 = 42a, so a=2 m/s².

Starting from rest, v=gt.
V=10×2 = 20 m/s.

At terminal velocity, net force is zero.
The object then moves with constant velocity.

Use s=½gt².
S=½×10×9 = 45 m.

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