Which of these is an example of a chemical change?

a. leaving cheese out to get moldy

b. smelling sprayed perfume

c. feeling ice melt on your skin

d. crushing ice with a hammer

What is a "hertz" in physics?

1. what type of plate boundary is associated with the formation of the oceian basin?

Name a force that opposes the movement of an object through water.

How do charges move through an insulated wire connected across a battery? Use the terms potential difference, current, conductor, and insulator in answer.

In general, covalent compounds do not conduct electric current in a water solution well because they do not dissociate into ions. a. True b. False

When a gas in a container is squeezed to half its volume, its density?

A ballet student with her arms and a leg extended spins with an initial rotational speed of 0.90rev/s. As she draws her arms and leg in toward her body, her rotational inertia becomes 0.80 kg⋅m2 and her rotational velocity is 4.1rev/s.

The power rating of a vacuum cleaner is 0.8 kilowatts. If you use the vacuum cleaner for 2.5 hours, how much energy does it use?

Which has more gravitational potential energy - - a cliff diver at the top of the cliff or a cliff diver at the bottom of the cliff?

A skydiver with a mass of 60 kg jumps from an airplane. Five seconds after jumping the force of air resistance is 300 N. What is the acceleration of the sky diver, five seconds after jumping?