Another (slightly more technical) name for kidney stones is "renal calculus".
I know this because we have met many times, and we are old friends.
The momentum of the rolling ball will have less momentum than before the collision and the stationary ball will have more momentum after the collusion.
Answer:the one with the smaller radius has the highest centripetal force
Explanation:
Answer:
Approximately 
, assuming friction between the vehicle and the ground is negligible.
Explanation:
Let 
denote the mass of the vehicle. Let 
denote the initial velocity of the vehicle. Let 
denote the spring constant (needs to be found.) Let 
denote the maximum displacement of the spring.
Convert velocity of the vehicle to standard units (meters per second):
.
Initial kinetic energy (
) of the vehicle:
.
When the vehicle is brought to a rest, the elastic potential energy (
) stored in the spring would be:
.
By the conservation of energy, if the friction between the vehicle and the ground is negligible, the initial 
of the vehicle should be equal to the 
of the vehicle. In other words:
.
Rearrange this equation to find an expression for , the spring constant:
.
Substitute in the given values 
, 
, and 
:
