Question

A railway engine of mass 4000kg is moving down a track at a constant speed of 3m/s

Answer 1

Step-by-step explanation:

the mass of 4000kg is just mentioned to confuse us. it has nothing to do with the solution of the question.

speed is distance/time, which is independent from any mass involved. and the question about the needed time is also independent from mass (but mass would be a factor, if the question were about e.g. the force of an impact of that train with a solid object).

so, any object of any mass, as it travels at 3m/s needs the same amount of time to move 180m.

it needs as many seconds as the number of times 3m fit into 180m, because

3m/s × x seconds = 180m

3m × x = 180m

x = 180m/3m = 60

so, it takes the train 60 seconds (= 1 minute) to move 180 meters when going 3m/s.

Answer 2

Answer:

1 minute
you just have to divide 180m by 3m= 60s