Newton's Laws Problem

Two boxes are side by side on a frictionless surface. A horizontal force is applied to move both boes.
(b) Determine the force that the 3.0 X 10¹ kg box applies to the 2.0 X 10¹ kg box.

http://img293.imageshack.us/my.php?image=48538466vd0.jpg

F = m * a
48 N = 60 kg * a
a = .8 m/s/s

F = m * a
F = 20 kg * .8 m/s/s
F = 16 N

The force is a bump.

据说牛顿发现了万有引力之后... : http://danhuaer.com/t/162798