A 1 000-kg experimental rocket sled on level frictionless rails is loaded with 50 kg of propellant.It exhausts the propellant in a 20-s "burn." If the rocket,initially at rest,moves at 150 m/s after the burn,what impulse is experienced by the rocket sled? A)1.1 x 10⁵ kg*m/s B)1.6 x 10⁵ kg*m/s C)1.5 x 10⁵ kg*m/s D)1.9 x 10⁵ kg*m/s

Question

Quizplus · Accepted Answer

We can use the principle of conservation of momentum to find the impulse experienced by the rocket sled. Before the burn, the total momentum of the system (rocket sled + propellant) is zero because the rocket is at rest. After the burn, the total momentum of the system is the momentum of the rocket sled alone, since all the propellant has been exhausted. Therefore:

(mass of rocket sled) x (final velocity of rocket sled) = impulse

Plugging in the numbers:

(1000 kg) x (150 m/s) = 1.5 x 10^5 kg m/s

Therefore, the impulse experienced by the rocket sled is 1.5 x 10^5 kg m/s. Choice C is the only option that matches this value.

A 1 000-Kg Experimental Rocket Sled on Level Frictionless Rails