Pakistan MCQs

Use W=Fd cosθ.
W=10×4×cos60° = 20 J.

Kinetic energy is ½mv².
K=½×4×9 = 18 J.

K=½mv².
K=½×2×100 = 100 J.

Potential energy change is mgh.
5×10×8 = 400 J.

Power is work divided by time.
P=600/3 = 200 W.

Energy transferred is Pt.
1000×20 = 20,000 J.

Net work equals the change in kinetic energy.
Kf=20+80 = 100 J.

ΔK=½m(v²-u²).
With m=2, ΔK=49-9 = 40 J.

Momentum is p=mv.
P=6×4 = 24 kg·m/s.

Impulse equals change in momentum.
J=3(8-2)=18 N·s.

Impulse is FΔt for constant force.
50×0.2 = 10 N·s.

Chemistry examines what matter is made of and how it behaves.
It also studies energy changes accompanying chemical processes.