An object accelerates from rest at a rate of 2m/s2. what will its velocity be after 4 seconds?

 i think that it would be 6m/s6 all you do is add em up.

This is what a calorimeter is used for simpler ex, to measure calories in food.

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.