Question

The bob of a simple pendulum of length 1 m has mass 100 g and a speed of 1.4 m/s at the lowest point in its path. Find the tension in the string at the instant

Answer 1

Length =  1 m.

Mass = 100 g. = 0.1 kg.

Velocity =  1.4 m/s.

At the lowest Point of the Path,

T = mg + mv²/r

⇒ T = 0.1 × 10 + 0.1 × (1.4)²/1

⇒ T = 1 + 0.196

∴ T = 1.196 N.

⇒ T = 1.2 N.

Hope it helps.