The car A has a weight of 4000 lb and is traveling to the right at 3 ft/s. Meanwhile a 2000-lb car B is traveling at 6 ft/s to the left. If the cars crash head-on, and at a time instant during the crash the impact force on A is 900 lb to the left, what is magnitude and direction of the impact force exerted on B at the

The answer is  a.first and third quarters 

Answer:   [a]:   "slate" .

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.