Question

A rocket sled rides on a frictionless track while a $800N$ force from the rockets accelerates the sled. Suddenly the rocket accidentally fire, applying a $800N$ force in the opposite direction. Identify which of the following is correct about the sled ?

• A. Slow down gradually to a stop
• B. Continue to accelerate
• C. Moves at a constant speed
• D. Reverse direction
• E. Not be affected at all

Answer 1

Answer: (C)

Moves at a constant speed

Since equal and opposite forces act on the rocket sled, the net force on the sled becomes zero. Hence the sled does not accelerate any longer, and therefore there is no further change in speed.

Hence the rocket sled moves at constant speed.