posted by kamish .
If you stand next to a wall on a frictionless skateboard and push the wall with a force of 40N, how hard does the wall push on you ? If your mass is 80kg show that your acceleration is 0.5m/s^2
Thw wall's force on the person pushing is the same (Newton's third law).
a = F/m = 40/80 = 0.5 m/s^2