Question

The engine of a toy train provides a constant force of 5N forward. What would happen if a child hit the train with a 8N backward force?

Answer 1

The result would be an acceleration in the backward direction.

Explanation:

I will assume that forward is the positive direction, the track is level and there is zero friction. The net force, `F_"net"`, on the train would be

`F_"net" = 5 N - 8 N = -3 N`

From Newton's 2nd Law, often written `F_"net" = m*a`, that must result in acceleration in the backward direction. If the train initially had a forward velocity, that acceleration would be what we commonly call deceleration. If it were intially stationary, it would start developing negative velocity.

I hope this helps,
Steve