Achild pushes a toy car down a hill. the child has a mass of 20 kg. the car has a mass of 1.6 kg and a speed of 7.4 m/s2. when the car has a gravitational potential energy of 30 j, what is the mechanical energy of the car?

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

State the below theories and give the name of the writer of the theory 1. wave theory 2. quantum theory 3. corpuscular theory 4. electromagnetic theory

Which of the following statements are evidence that gases do not always behave ideally? check all that apply.? a. co2 gas becomes dry ice (solid co2) at 1 atm and –78.5 °c. b. when two gases are mixed, they follow dalton\'s law of partial pressures. c. at 4 k and 1 atm, helium is a liquid. d. it is impossible to compress a gas enough so that it takes up no volume.