Question

For a 60 kg mass, if the friction force is 40 N, the magnitude of the applied force required to accelerate the object at 4.0m/s^2 is ____x10^2 N (Give your answer with the correct number of Significant digits and do not include units)

Note: Let East be the positive direction

Answer 1

According to Newton's second law:

$$ma=F-f,\\ F=ma+f=2.8\cdot10^2\text{ N}$$