What happens when the temperature of a substance decreases significantly?

A.

Most substances will expand.

B.

Most substances will gain atoms.

C.

Most substances will disappear.

D.

Most substances will contract.

Which of the following best describes work being done by someone's arms? a. a child building a sand castle b. a mother holding a baby c. a boy pushing on a tree d. a traveler carrying luggage

A wave has a wavelength of 125 meters is moving at a speed of 20 m/s. What is it's frequency?

A 50 g ball falls off a desk and travels a distance of 1 m. How far will a 100 g ball travel?

Why would a person choose to tie a helium-filled balloon to a child's wrist instead of simply having the child hold on to it? A. Helium is less dense than air, so it will float above air if the child lets go of the balloon. B.

In the case of mechanical waves, what causes or determines the speed of the waves, the frequency of the waves, and the wavelengths of the waves?

A machine with a mechanical advantage of 10 is used to produce an output force of 250 newtons. What input force is applied to this machine

Why do you float in space

How does physical change affect the identity of a substance

A scientist pours grape juice on three identical white shirts He then uses three different cleaning products on the shirts and measures how clean they get what is the independent variable in this experiment

What part of the atom does nuclear radiation come from?