I would say Emotional health. Just because it is more sensable
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:
1500 per second.
Explanation:
vibrations = 1.5 kilohertz
1.5×1000=1500
the answer is 1500 per second.