Question
Superman must stop a 110-km/h train in 100m to keep it from hitting a stalled car on the tracks. The train's mass is 3.6 × 105 kg.
Answers
Henry
Vo = 110km/h = 110000m/3600s = 30.56 m/s
V^2 = Vo^2 + 2a*d = 0
a = -(Vo^2)/2d = -(30.56^2)/200 = -4.67
m/s^2.
F = m*a = 3.6*10^5 * (-4.67) = -1.68*10^6 N.
Note: The negative sign means that the force opposes the motion.
V^2 = Vo^2 + 2a*d = 0
a = -(Vo^2)/2d = -(30.56^2)/200 = -4.67
m/s^2.
F = m*a = 3.6*10^5 * (-4.67) = -1.68*10^6 N.
Note: The negative sign means that the force opposes the motion.