A model rocket with a mass of 0.181 kg is launched into the air with an initial speed of 92 m/s. How much kinetic energy will the rocket have at a height of 164 m? Assume there is no wind resistance.

303 J - 747 J - 634 J - 444 J

I have tried taking the initial KE with 1/2.18192^2 and subtracted the final potential energy. 1819.8164. This gets me 475, which isn't any of the choices. I picked 444 J since it was the closest, but it was wrong.

Question

Physics

Marcus Francis

5 October, 09:21

A model rocket with a mass of 0.181 kg is launched into the air with an initial speed of 92 m/s. How much kinetic energy will the rocket have at a height of 164 m? Assume there is no wind resistance.

303 J - 747 J - 634 J - 444 J

I have tried taking the initial KE with 1/2.18192^2 and subtracted the final potential energy. 1819.8164. This gets me 475, which isn't any of the choices. I picked 444 J since it was the closest, but it was wrong.

+2

Answers (1)

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Kellen Cunningham · Answer 1

Kinetic energy is the energy that is possessed by an object that is moving or in motion. It is calculated by one-half the product of the mass and the square of the velocity of the object. It is independent of the height for this case. So, we only use the mass of the rocket which is 0.181 kg and the velocity which is equal to 92 m/s. We calculate as follows:

KE = mv^2 / 2KE = 0.181 kg (92 m/s) ^2 / 2KE = 765.992 kg-m^2/s^2 or 765.992 J

Therefore, the closest answer to the value we got would be the second option, 747 J.