Chapter 5: Laws of Motion

Q1. A 5 kg block is pulled with force 20 N on a frictionless surface. Find acceleration.

Solution

F = ma
a = F/m = 20/5 = 4 m/s²

Q2. What is the tension in a rope when a 10 kg mass hangs at rest?

Solution

T = mg = 10 × 9.8 = 98 N

Q3. A car of mass 1000 kg moves in a circle of radius 20 m at 10 m/s. Find the centripetal force.

Solution

F = mv²/r = 1000 × 100/20 = 5000 N