What is an atom's nucleus made of? (2 points)
protons and electrons
protons only
protons and neutrons
neutrons only

Free runners jump long distances and land on the ground or a wall. how do they apply newton’s second law to lessen the force of impact?

**urgent** roberto plans to use two transformers to reduce a voltage of 120 v to 4 v. he uses a transformer that has 300 coils in the primary winding and 50 coils in the secondary winding. he has four other transformers, as listed in the table. which transformer should roberto use to have an ending voltage of 4 v? a- w b-xc- yd- z

If you put a helium-filled balloon in the refrigerator, what will happen?