Question

One end of the rope is fixed to vertical wall and other end pulled by horizontal force of 20 N. The shape of flexible rope is shown in figure. The mass of rope is-

• A. 2 kg
• B. 3 kg
• C. 3.5 kg
• D. 4.5 kg

Answer 1

Answer: (C)

3.5 kg

Answer 2

.(3)

Sol.

T sin q = 20

T cos q = W

tan q = $\frac { 20 } { \mathrm {~W} }$

W = 20 cot q

W = 20 cot 30⁰

W = 20 $\sqrt { 3 }$ = 20 × 1.732

Weight W = 34.64 N

mass ‘m’ = $\frac { \mathrm { W } } { \mathrm { g } }$ = 3.5 kg.