Pretty sure it’s C. all the others are speeding up. acceleration means gradually (over time) getting faster. So it’s C.
Explanation:
Mass of bumper cars, 
Initial speed of car A, 
Initial speed of car Z, 
Final speed of car A after the collision, 
We need to find the velocity of car Z after the collision. Let it is equal to
. Using the conservation of momentum as :




So, the velocity of car Z after the collision is (-12 m/s). Hence, this is the required solution.
Answer: Object B
Explanation: Acceleration is directly proportional to force and inversely proportional to mass. It implies that more massive objects accelerates at a slower rate.
Answer
b. the number of atoms in each molecule.
Explanation: