Ball A, with a mass of 1.75 kg, moves with a velocity 3.50 m/s. It collides with
a stationary ball B, with a mass of 2.50 kg. After the collision, ball A moves in
a direction 55.0° to the left of its original direction, while ball B moves in a
direction 35.0° to the right of ball A's original direction. Calculate the velocity
of each ball after the collision.

You can find results and justify them? you can test your hypothesis

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.

How are period and frequency related to each other? dperiod is the reciprocal of frequency.