A 30 kg child sits on the right end of a see-saw 1 m from the axis. If a 20 kg child sits on the left end of the see-saw 2 m from the axis, what will happen?
A. the see-saw will tilt to the right
B. the see-saw will tilt to the left
C. the see-saw will balance
D. need more information to predict outcome
Answer: B