# AP® US History

Free Version
Moderate

CLMECH-D3FPU2

Many satellites have small thrusters and a bit of extra fuel they can use to adjust their orbits. A 1,220 kg satellite in a stable low Earth orbit is moving with an initial speed of 7.75 km/s. It fires its thrusters for 4.25 sec, then its final speed is 7.75 km/s, but in a new direction about 1.13° off its original direction.

What was the force exerted by the thruster?

A

$F=0$, because the speed did not change.

B

$F=0$, because items in space are weightless.

C

$F = 1.25\:kN$

D

$F = 43.9\:kN$

E

$F = 72.8\:kN$