A 650 newton skydiver jumps out of a plane at an altitude of 5000m. 8 seconds after he stops accelerating, he is moving at 50m/s. How large is the air resistance acting against him?
less than 650n
Equal to 650 N
Greater than 650N
Is this enought information to answer this?
Newton's first law says:
"The velocity of a body remains constant unless the body is acted upon by an external force"
If the skydiver falls at a constant speed (not accelerating), this means that his weight due to gravity is off-set (balanced) by some external force, of which the only one is air-resistance.
Therefore there is enough information to tell which of the three given answer is correct, remembering that any unbalanced force will cause acceleration or deceleration.