A 14.0 ft long see-saw has its fulcrum in the middle and has four kids sitting on it. A 680 lb kid sits on the left end and a 76.0 lb kid sits 2 50 ft in front of him A 94.0 lb kid sits on the right end and another kid sits 2 50 ft in front of him. How much must this kid weigh to balance the see-saw?

Match each vocabulary term to its definition. 1. electrons neutral subatomic particles found in the nucleus of the atom 2. neutron lowest energy position of an electron in an atom 3. photon the path of an electron around the nucleus of an atom 4. ground state negatively charged, subatomic particles 5. protons packet of energy of specific size 6. element substance with only one type of atom 7. orbital positively charged, subatomic particles found in the nucleus of the atom

Holes drilled several kilometers into earth’s crust provide direct evidence about earth’s interior in the form of

Two 2.0-cm-diameter disks face each other, 1.0 mm apart. they are charged to ±10 nc. what is the electric field strength between the disks? a proton is shot from the negative disk toward the positive disk. what launch speed must the proton have to just barely reach the positive disk?