How fast would that train go?
Science • February 2011 • Views: 767
Here’s my reasoning:
Gravity acceleration constant: 10 m/s2
No friction or other loss of energy
Max depth of tunnel: 500m (roughly 1500 ft)
Therefore:
Energy of 1kg of matter moving at max speed in tunnel is equal to the potential energy of that 1kg at the top of the ramp, which is:
D x M x A = E
500m x 1kg x 10m/s2 = 5000J
The moving energy is equal to:
M x V2 = E
1 kg x V2 = 5000J
V2 = 5000m/s2
V = 70m/s
70m/s is 4000m/min, 240km/h, 150 mph
QED?
