How do electric motors work? A. They convert kinetic energy into electrical energy

B. They convert electrical energy into kinetic energy

C. They convert chemical energy from gasoline into kinetic energy

D. They convert mechanical energy into potential energy

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

20. threshold braking in the vehicle's braking system occurs when a. the brake pedal is pushed, heel on floorboard, with full foot pressure. b. the brakes are exerting full braking power, without traction loss. c. the driver begins pushing down the brake pedal, with moderate slowdown. d. the brakes just begin to take hold with a gradual slowdown.

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