What is the efficiency of a machine that miraculously converts all the input energy to useful output energy?

A 96lb boy is standing in an elevator. Find the force on the boy's feet when the elevator (a) stands still (b) moves downward at a constant velocity of 3 ft/d (c) accelerates downward with an acceleration of 4.

The aluminum block is initially at a temperature of 300 K. It is then brought into contact with 1 mole of gas particles at a temperature of 400 K and constant volume.

How is solubility of a gas affected when an increase of pressure occurs?

What type of rock forms due to heating and cooling?

You're driving along at 25m/s with your aunt's valuable antiques in the back of your pickup truck when suddenly you see a giant hole in the road 55 m ahead of you. fortunately, your foot is right beside the brake and your reaction time is zero!

1. a substance with a pH of 3 2. a substance with a pH of 10 3. a substance with a pH of 7 4. an indicator 5. a scale that represents the concentration of H30+, 0-14 A.) phenolphthalein B.) base C.) pH scale D.) neutral E.) acid

An advertisement uses a movie star holding a bottle of perfume. This ad is an example of which of the following? A. an appeal of association. B. an appeal to reason. C. an appeal to economics. D. an appeal to patriotism.

An example of an unbalanced force is

When the atom's electrons step down to lower energy levels in a thin cloud of hot gas, what is produced?

Which is the relationship between algae and fungus? Options: Parasitism. Commensalism. Mutualism.