What is the efficiency of a device that takes 400J of heat and does 120J of work while giving off 280 J of heat

A large block of plastic is solid except for an air-filled void in the center of the block. The void is in the shape of a double concave lens. A ray of light traveling parallel, but slightly above or below the central axis of the "lens" will: A.

Describe 1 way to reduce the shortage of food for a growing human population.

How is work related to force and displacement?

What are three habits that you plan to change in your own life to ensure that you age healthier?

Compare the momentum of a 6,300-kg elephant walking 0.11 m/s and a 50-kg dolphin swimming 10.4 m/s. your answer

When distances were carefully measured from Earth to globular clusters above and below the Milky Way plane (where our view of them is not obscured by interstellar dust and gas), their distribution was found to be

Imagine you transfer heat into a gas. This heat splits up in two different ways: Additional thermal energy making the gas hotter and "fuel" for the gas to do work. Let's suppose, 64% of the transferred heat transforms into thermal energy.

How much heat is absorbed by a 61g iron skillet when its temperature rises from 5oC to 29oC?

Explain the relationship between motion and frame of reference.

Two students are looking at a brightly lit full Moon, illuminated by the reflected light from the Sun. Consider thefollowing discussion between the two students about what the spectrum of moonlight would look like.