OPTIONS :
A.) the force that the ball exerts on the wall
B.) the frictional force between the wall and the ball
C.) the acceleration of the ball as it approaches the wall
D.) the normal force that the wall exerts on the ball
Answer: D.) the normal force that the wall exerts on the ball
Explanation: The normal force acting on an object can be explained as a force experienced by an object when it comes in contact with a flat surface. The normal force acts perpendicular to the surface of contact.
In the scenario described above, Erica's tennis ball experiences an opposite reaction after hitting the wall.This is in relation to Newton's 3rd law of motion, which states that, For every action, there is an equal and opposite reaction.
The reaction force in this case is the normal force exerted on the ball by the wall perpendicular to the surface of contact.
The kinetic energy K given to the helium nucleus is equal to its potential energy, which is

where q=2e is the charge of the helium nucleus, and

is the potential difference applied to it.
Since we know the kinetic energy, we have

and from this we can find the potential difference:
Yes, parallax affects the precision of a measurement that you make. It introduces an error in the order of the parallax. It will cause the measurement to be different from the real answer. Hope this answers the question. Have a nice day.
An alcohol functional group is called a hydroxyl group.