Question

The acceleration with which an object of mass $100kg$ be lowered from a roof using a cord with a breaking strength of $60kg$ weight without breaking the rope is:

• A. $2m/se{c}^2$
• B. $4m/se{c}^2$
• C. $6m/se{c}^2$
• D. $10m/se{c}^2$

Answer 1

The correct option is B $4m/se{c}^2$

Tension $T$ in the cord is

$100g-T=100a$

acceleration should be such that the resultant force do not cross $60gN$

$100g-60g=100a$

$400=100a$

$a=4m/s^2$