Superman must stop a 120km/h train in 150m to keep it from hitting a stalled car on the tracks.If the train's mass is 3.6x10^5kg,how much force must he exert?Compare to the weight of the train (give as%).

Answer 1

120 *10^3 meters/3600 seconds = 33.33 m/s

easy way - use energy

Force * distance = work = change in (1/2)mv^2

F (150) = (1/2)(3.6*10^5)(33.33)^2

F = 2000 * 10^5 = 2 *10^8 Newtons

Weight = m g = 3.6*10^5 * 9.81
= 35.3 *10^5

100 * F/weight = 10^2 * 2*10^8/35.3*10^5

= .0566 * 10^5 = 5660 percent for what that is worth :)

Answer 2

wow

Answer 3

wow

Answer 4

i dont understand that question at all