Newton's 2nd Law: Force, Mass, & Acceleration

[Alan3030]

Apologies for what I assume is a rookie question. Given F=ma if you have a 1 kg object traveling in e.g. space say x @ 100m/s then F = 0 on that object. If you have another 1kg object say y sitting at 0 m/s, F=0. If they impact there must be force involved? Does negative acceleration give you a F? if so what's the math?

 

[gleem]

Yes a force is involved anytime there is an acceleration an increase in velocity or a deceleration a decrease in velocity. A deceleration is a negative acceleration. Force on an object is equal to the mass of the object times the instantaneous time rate of change of its velocity.

 

[Alan3030]

Thanks that makes sense now :)