Question

1. the acceleration of a 20 kg - object decreases from 8.0 m/s2 to 3.0 m/s2. what is the change of the net force on the object? (hint: 2 step problem) clear all 160 n -220 n 100 n -100 n

Explanation:

Step1: Find initial net - force

According to Newton's second law $F = ma$. The initial acceleration $a_1=8.0\ m/s^2$ and mass $m = 20\ kg$. So the initial net - force $F_1=ma_1=20\times8.0 = 160\ N$.

Step2: Find final net - force

The final acceleration $a_2 = 3.0\ m/s^2$ and mass $m = 20\ kg$. So the final net - force $F_2=ma_2=20\times3.0=60\ N$.

Step3: Calculate change in net - force

The change in net - force $\Delta F=F_2 - F_1=60 - 160=- 100\ N$.

Answer:

-100 N