Sandy has a mass of 20 kg and is hanging from the ankle of David, whose mass is 110 kg. Tim hanging from Sandy's ankle and has a mass of 300 kg. All three are ascending upward with acceleration = +3.2m/s². David is the source of upward thrust. What force does Tim exert on Sandy? Positive is up, negative is down.

a. 2940 N

b. 3655 N

c. 3900 N

d. 4130 N

e. 4401 N

In the previous problem, suppose instead the force Tim exerts on Sandy were 4000N. What force does David exert on Sandy?

a. 3196 N

b. 3260 N

c. 4196 N

d. 4260 N

e. 4640 N