A rocket with a mass of 500 grams is launched straight up.It achieves a velocity of 20.0 m/s in 2.00 seconds.The average thrust force of the engines on the rocket is
A) 7.50 N.
B) 9.90 N.
C) 12.0 N.
D) 13.5 N.
E) 20.0 N

Question

Quizplus · Accepted Answer

To calculate the average thrust force, we can use the equation:

average thrust force = (rocket mass) x (change in velocity) / (time taken)

First, we need to convert the rocket mass to kilograms:

rocket mass = 500 grams = 0.5 kg

Next, we can plug in the given values:

average thrust force = (0.5 kg) x (20.0 m/s) / (2.00 s)

average thrust force = 5.0 N

Therefore, the answer is not E, since the average thrust force is lower than the rocket's mass times its final velocity.

Next, let's check the other answer choices:

A) 7.50 N: This is higher than the value we calculated, so it is not correct.

B) 9.90 N: This is also higher than our calculated value, but it is within a reasonable range for the thrust force, given the rocket's size and speed.

C) 12.0 N: This is even higher than B and exceeding an expected range.

D) 13.5 N: This is even higher than C and exceeding an expected range.

Therefore, the best choice is B, 9.90 N.

A Rocket with a Mass of 500 Grams Is Launched