Afreight train has a mass of 1.5 x 10^7 kg. if the
locomotivecan exert a constant pull of 7.5 x1^5 n, how long does it
take toincrease the speed of the train from rest to 80 km/h?

Plss anybody know how to do this? ? i need the answers from a through d

Imagine you had to physically add electrons, one at a time, to a previously neutral conductor. you add one electron very easily, but the second electron requires more work. in your initial post to the discussion, explain why this is. also, what happens to the work needed to add the third, fourth, fifth, and subsequent electrons

A20 cm long spring is attached to a wall. the spring stretches to a length of 22 cm when you pull on it with a force of 100 n. what is the spring constant