# physics

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a mass of gas emitted from the rear of toy rocket is initially 0.2kg/s. if the speed of the gas relative to the rocket is 40m/s and the mass of the rocket is 4 kg what is the initial acceleration of the rocket

• physics -

The reaction force is
F = Vexhaust*(mass flow rate)
= 40*0.2 = 8 Newtons

The acceleration rate is F/m = 2 m/s^2

Since that is less than g (which is 9.8 m/s^2), it won't leave the ground. It better have wheels if it is going anywhere.

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