If the speed of the F=4000 lb car is plotted over the 30-s time period. Find the variation of the traction force F needed to cause the motion from 20s to 30s.
1) 124.2 lb
From the graph for
0 < t < 20s:
Equation of motion:
So, the traction force needed for the car to travel from 20s to 30s is 124.2 lb.