An ion rocket engine obtains thrust by firing out charged atoms (ions) at very high speeds. If 21.0 grams of propellant are ejected at a speed of 0.0131% the speed of light (c = 3x108 m/s) every second, what would be the acceleration on the 820 kg rocket?

When considering gravity acceleration and the force of acceleration, what must be true? a. the direction of acceleration must be perpendicular to the direction of the force. b. the direction of the force and the direction of acceleration must be the same as each other. c. the direction of the force and the direction of acceleration must be opposite of each other. d. the mass of the body must be the same as the acceleration of the body.