Hi everyone,
Basically I was thinking about F=ma and found abit of a problem for which the equation falls down on,
Say there was a lorry mass 1000 kg and it was travelling down a road at 20 ms^-1 but was not accelerating at all it was just travelling at a constant speed, then by Newtons second law the lorry should have a force of 1000 x 0 = 0 N, however if this lorry was to hit a tree for instance, then obviously it is going to hit with a force, a massive force...not a force of 0, could some one explain to me why this is?
Thanks, Chris.