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 special feature of the upper mantle is the asthenosphere.It is located just below the lithosphere and is made up of rocks that is fluid and can move.The fluidity of these rocks powered the movement of the tectonic plates on the earths crust.Circular convection cycles in the hot,fluid upper mantle rock move the plates over the surface of the earth.
The magnitude of the electric force on the charge is 5 N.
<h3>Magnitude of force on the charge</h3>
The magnitude of force on the charge is calculated as follows;
F = Eq
where;
- E is electric field
- q is magnitude of the charge
F = 100 N/C x 0.05 C
F = 5 N
Thus, the magnitude of the electric force on the charge is 5 N.
Learn more about electric force here: brainly.com/question/20880591
#SPJ1
<h3><u>Answer</u>;</h3>
1600 years
<h3><u>Explanation</u>;</h3>
- Half life is the time taken for a radioactive isotope to decay by half of its original amount.
- We can use the formula; N = O × (1/2)^n ; where N is the new mass, O is the original amount and n is the number of half lives.
- A sample of radium-226 takes 3200 years to decay to 1/4 of its original amount.
Therefore;
<em>1/4 = 1 × (1/2)^n</em>
<em>1/4 = (1/2)^n </em>
<em>n = 2 </em>
Thus; <em>3200 years is equivalent to 2 half lives.</em>
<em>Hence, the half life of radium-226 is 1600 years</em>
22. reduction
25. Le Chatelier's principle
