Question

Diwali rocket is ejecting 50 g of gases/s at a velocity of 400 m/s. The accelerating force on the rocket will be

• A. 22 dyne
• B. 20 N
• C. 20 dyne
• D. 100 N

Answer 1

Answer: (B)

20 N

Answer 2

The accelerating force on the rocket = upward thrust $=\frac{\Delta m}{\Delta t}\cdot u$ Given, $\frac{\Delta m}{\Delta t}=50\times {{10}^{-3}}kg/s,\,\,v=400\,\,m/s$ So, accelerating force $=50\times {{10}^{-3}}\times 400$ $=20\,\,N$