physics problems(3)

Question

6. a 60kg skydiver is falling at constant speed near the suface of Earth. the magnitude of the force of air friction acting on the skydiver is approximately(1) 0N (2) 6N (3) 60N (4) 600N
7. which person has the greatest inertia? (1) a 110kg wrestler reasting on a mat (2) a 90kg man walking at 2m/s (3) 70kg long sistance runner traveling at 5m/s (4) a 50kg girl sprinting at 10m/s

Explain in details !!!

Answer 1

6. Since the skydiver is falling at constant speed, the net force acting on him is zero. That is, the air friction just balances the weight of the skydiver. Thus the answer is option (4).

7. Mass is a measure of inertia. The one with greatest mass possesses the greatest intertia. The answer is thus option (1).