An engine does 10 j of work and exhausts 25 j of waste heat during each cycle.
what is the thermal efficiency?
i did it like
eff = = 0.67 = 67%
but my homework said it was incorrect
so i tried it this way
eff = = 0.4 = 40%
but that is also incorrect, so what am i doing wrong?

Initially, a particle is moving at 5.33 m/s at an angle of 37.9° above the horizontal. two seconds later, its velocity is 6.11 m/s at an angle of 54.2° below the horizontal. what was the particle's average acceleration during these 2.00 seconds in the x-direction (enter first) and the y-direction?

In an experiment, how can i change human errors? be specific.

The combining of light nuclei is called blank. blank as in not actually blank. you know what im tryin to say.