NAT Physics MCQs

Internal forces cancel in pairs within a system.
With no net external impulse, total momentum remains constant.

Use v=u+at with u=0.
V=0+3×4 = 12 m/s.

Use v=u+at.
V=5+2×6 = 17 m/s.

Acceleration is change in velocity divided by time.
(5-20)/3 = -5 m/s².

Use s=ut+½at² with u=0.
S=½×2×25 = 25 m.

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.

Use s=½gt².
S=½×10×9 = 45 m.

At maximum height, final vertical velocity is zero.
0=20-10t gives t=2 s.

Use v²=u²-2gh with v=0.
0=400-20h, so h=20 m.

Newton's second law gives F=ma.
F=5×4 = 20 N.