C. inertia. the man is sent flying off the bus because of his weight and the sudden stop of the bus. this effect is called inertia. an example of gravity would be throwing an apple up and having it come to the ground. an example of weight would be putting a man and an elephant on a scale and having the elephant come down while the man goes up.
Who Figured This Out? The American astronomer Edwin Hubble made the observations in 1925 and was the first to prove that the universe is expanding. He proved that there is a direct relationship between the speeds of distant galaxies and their distances from Earth. This is now known as Hubble's Law.
Explanation:
Momentum before = momentum after
m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂
(65 kg) (0 m/s) + m (0 m/s) = (65 kg) (-3.5 m/s) + m (4 m/s)
m ≈ 57 kg