The planet venus, our moon, and halley's comet all
a.) are larger than the earth
b.) are composed of primarily hydrogen.
c.) change speed dramatically as they orbit.
d.) have highly predictable orbits around the sun.

Ahot-air balloonist, rising vertically with a constant speed of 5.00 m/s releases a sandbag at the instant the balloon is 40.0 m above the ground. after it is released, the sandbag encounters no appreciable air drag. compute the velocity of the sandbag at 0.250 s after its release.

What is the final velocity of the initial velocity of 25 and -50?

The mass of the sun is 1.99×1030kg and its distance to the earth is 1.50×1011m. what is the gravitational force of the sun on the earth?