A heat engine produces 8200 j of heat while performing 3200 of useful work. what is the efficiency of this engine? (i'm doing something wrong.)

Why would an orange roll of your cafeteria tray if you stopped suddenly

Nuclear winter story. A crazy president is trying to solve the global warming problem and has successfully built a powerful H-bomb.

The conductors that carry the current to electrical devices and? equipment are the heart of all electrical systems. There are associated? whenever current flows through a conductor. Select one: a. relay / responses b. service / effects c.

Why is friction between moving parts of machines undesirable?

What planet has the least amount of inertia

A high-mass star has more "fuel" than a low-mass star. which lives longer? why?

Suppose that, while lying on a beach near the equator of a far-off planet watching the sun set over a calm ocean, you start a stopwatch just as the top of the sun disappears. you then stand, elevating your eyes by a height h = 1.

Suppose you want to know if the color of peoples hair affects how warm it can keep their heads. describe the skills you would use to conduct an experiment to test your inquiry

The mass is increased by a factor of four. What is true about the period? Choose the best answer. The period remains unchanged. The period increases by a factor of four. The period is halved. The period doubles.

What does law of conservation of mass mean?