Just as no mechanical device can be 100% efficient, no heat engine can transfer 100% of its heat to a single object. some of the heat energy must be wasted (released into the environment). we have a heat engine that produces 150 j of heat, does 40 j of work, and emits 110 j into another system. what is the efficiency of the heat engine? show your work.

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?

What happens when you slowly pulled the carboard?

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.