What does an alpha particle consist of?
a. 1 proton and 1 neutron
b. 1 proton and 2 neutrons
c. 2 proton and 2 neutrons
d. 2 proton and 4 neutrons

Give an example for each of the following situations: 1) negative acceleration, but positive velocity 2) positive acceleration and positive velocity 3) positive acceleration, but negative velocity 4) negative acceleration and negative velocity 5) positive velocity and no acceleration