Question

A 60 kg student in a rowboat on a still lake decides to dive off the back of the boat. The studen'ts horizontal aceleration is 2.0 m/s2 while in contact with the boat. What horizontal force does the student exert on the boat?
a 30N toward the back of the boat
b 120 n toward the front of the boat
c 30 n toward the front of the boat
d 120 n toward the back of the boat

Answer 1

As per the third law of Newton, the force exerted by the boat over the student is equal in magnitude to the force that the student exerted on the boat.

So, calculate the force on the student using the second law of Newton, Force = mass * acceleration.

Force on the student = 60 kg * 2.0 m/s^2 = 120 N.

=> horizontal force exerted by the student on the boat = 120 N

Answer: option d. 120 N. toward the back of the boat.

Of course it is toward the back because that is where the student jumped from..