The engine of a locomotive exerts a constant force of 8.1*10^5 n to accelerate a train to 68 km/h. determine the time (in min) taken for the train of mass 1.9*10^7 kg to reach this speed from rest.

443.1 s

Explanation:

Given

Engine of a locomotive exerts a force of

Mass of train

Final speed (v)

F=ma

so

and acceleration is

Explanation:

It is given that,

Force acting on the engine,

Initial speed of the engine, u = 0 (at rest)

Final speed of the engine, v = 68 km/h = 18.88 m/s

Mass of the train,

We need to find the time taken by the train. Firstly, we will find the acceleration of the engine from Newton's second law of motion as :

Now using first equation of motion to find time taken as :

t = 449.52 seconds

or

t = 7.49 minutes

So, the time taken for the train to reach this speed is 7.49 minutes. Hence, this is the required solution.

the small 0.38-kg slider is known to move from position a to position b along the vertical-plane slot. determine (a) the work done on the body by its weight and (b) the work done on the body by the spring. the distance r = 0.70 m, the spring modulus k = 154 n/m, and the unstretched length of the spring is 0.53 m

explanation:

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