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.

Respuesta :

The force of the object is calculated as: 
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, [tex]m = 50,000 kg[/tex]

coefficient of friction for steel, [tex]\mu= = 0.002[/tex]

Velocity of the locomotive is [tex]v = 10 m/s[/tex]

By conservation of energy it can be written as:

[tex]KE = E[/tex]

Here, E is the energy because of friction.

Now,

[tex]KE = \frac{1}{2}\times m\times v^2[/tex]

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

Now energy of the friction can be written as,

[tex]E= F\times d =\mu\times N = \mu\times mg[/tex]

Here, [tex]\mu[/tex] is the coefficient of friction , m is the mass and g is the acceleration due to gravity.

Therefore

[tex]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)}[/tex]

Substitute all the variables.

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

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