A 1,450-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 160 m/s after the burn,what impulse is experienced by the rocket sled? A) 0.1 × 10⁵ kg⋅m/s B) 1.5 × 10⁵ kg⋅m/s C) 2.4 × 10⁵ kg⋅m/s D) 8 × 10⁵ kg⋅m/s E) 2.6 × 10⁵ kg⋅m/s

Question

Quizplus · Accepted Answer

We can use the impulse-momentum theorem which states that the impulse on an object is equal to its change in momentum.

Initial momentum of the rocket sled = 0 kg*m/s 
Final momentum of the rocket sled = (1450 + 50) kg * 160 m/s = 240,000 kg*m/s

Change in momentum = 240,000 kg*m/s - 0 kg*m/s = 240,000 kg*m/s

The impulse experienced by the rocket sled is equal to the change in momentum, which is 240,000 kg*m/s.

Therefore, the best choice is C, 2.4 x 10^5 kg*m/s.

A 1,450-Kg Experimental Rocket Sled on Level Frictionless Rails Is