Question

The four balls in FIGURE Q6.9 have been thrown straight up. They have the same size, but different masses. Air resistance is negligible. Rank in order, from largest to smallest, the magnitude of the net force acting on each ball. Some may be equal. Give your answer in the form $a>b>c=d$and explain your ranking.

Short answer

The magnitude of net forces of each ball is ranked in order:$d>c=b>a$

Step-by-step solution

Calculation of net force for each ball given in figure Q6.9

a.$F_{net,a}=0.2\times 9.81=1.962N$

b.$F_{net,b}=0.3\times 9.81=2.943N$

c.$F_{net,c}=0.3\times 9.81=2.943N$

d.$F_{net,d}=0.4\times 9.81=3.924N$

Rank in order, from largest to smallest, the magnitude of the net force acting on each ball. 

From the step 1 results, we get ranked in order: $d>c=b>a$