A 50,000 kg locomotive is traveling at 10 m/s when its engine and brakes both fail. How far will the locomotive roll before it comes to a stop? Assume the track is level.

Verified Answer :

The force of the object is calculated as: 
F 
= μ x normal force=μ x m x g
F = 0.5(50000kg)(−9.8ms2)F =−245000N


a = F/ma = −245000N/50000kga =−4.9

t = (v−v0) / at = (0−10) / −4.9t =2s

Answer:

2551.02 m

Explanation:

Given that, the mass of a locomotive is, \(m = 50,000 kg\)

coefficient of friction for steel, \(\mu= = 0.002\)

Velocity of the locomotive is \(v = 10 m/s\)

By conservation of energy it can be written as:

\(KE = E\)

Here, E is the energy because of friction.

Now,

\(KE = \frac{1}{2}\times m\times v^2\)

Here, m is the mass, v is the velocity of an object.

Now energy of the friction can be written as,

\(E= F\times d =\mu\times N = \mu\times mg\)

Here, \(\mu\) is the coefficient of friction , m is the mass and g is the acceleration due to gravity.

Therefore

\(1/2\times m\times v^2 = \mu\times m\times g\times d\\1/2\times v^2 = \mu\times g\times d\\d=\frac{1 v^2}{2(g\times \mu)}\)

Substitute all the variables.

\(d= \frac{10^2}{2(9.8\times 0.002)}\\\\d=2551.02 m\)

The distance traveled by the locomotive ball before stopping is 2551.02 m