What average force is experienced by the rocket during the burn?

A 1100 kg rocket sled at rest on level frictionless rails is loaded with 25 kg of propellent. It exhaust the propellant in a 20 seconds "burn". The rocket moves at 120 m/s after the burn. What average force is experienced by the rocket during the burn?


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|||Acceleration of the rocket:


V = U+at


120 = 0 +a*20


a = 120/20


a = 6m/s虏





Force = m*a


Force = 1100 *6


Force = 6600N|||Use Newton's second Law Fnet = mass x acceleratiion





Find acceleration using a = (vf-vi)/ change in time





a = (120 - 0)/20





a = 60 m/s^2





Plug into Fnet=ma





Fnet = (1100 kg + 25 kg) (60 m/s^2)





Fnet = 67500 N in the direction of the motion





There you have it, the answer is 67500 N in the direction of the motion