Question

A three-tiered birthday cake rests on a table. From bottom to top, the cake tiers weigh 17 N, 12 N, and 7 N, respectively. What is the magnitude and direction of the normal force acting on the second-tier

Answer 1

It takes 7 N to support the top tier.

12 N are required to support the middle tier

Thus a total force of 19 N is directed to the bottom tier and must be supplied to support the middle tier.