Linear Momentum and Second Law of Motion: Practice Problem & Solution
A rocket of mass 6000 kg is set for vertical firing. If the exhaust speed be 1 km/s how much gas must be ejected to give the rocket an upward acceleration of 20 m/s² (neglect gravity) :-
Short Solution (Best for NEET):
To solve this problem, we apply the core principles of Linear Momentum and Second Law of Motion. Understanding the underlying formula is key to arriving at the correct answer below:
According to Newtons second law of motion
F= v. dm/dt
so, acceleration = v. (dm/dt)/m
⇒ 20 m/s² = 1000 ×(dm/dt)/6000
⇒dm/dt = 120 kg/sec
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