PLEASE HELP!! AP PHYSICS B QUESTION!! What is the net force required for a 1.5 X 105 kg train car......

What is the net force required for a 1.5 X 105 kg train car to move from 20 km/h to 60 km/h over 100 meters?


a. 9.3 X 104 N

b. 1.8 X 105 N

c. 4.4 X 105 N

d. 9.3 X 105 N

e. 4.5 X 106 N

We will need to use F = ma to find F. We have m, but not a. However, we have all the information we need to find a. Note that values for v are converted to m/s.

Use:

Vf^2 = Vo^2 + 2ax

(16.68)^2 = (5.56)^2 + 2a(100)

277.78 = 30.86+ 200a

a = 1.24 m/s^2

Now use this value for a in F = ma:

F = ma

F = (1.5 * 10^5)(1.24)

=180,000 N or 1.8 * 10^5