Explanation:
The relation between force, mass and acceleration is as follows.
F = ma
or, a = [tex]\frac{F}{m}[/tex]
As two blocks are in contact with each other. Hence, total mass will be as follows.
mass = 5 kg + 2 kg
= 7 kg
Now, we will calculate the acceleration as follows.
a = [tex]\frac{F}{m}[/tex]
= [tex]\frac{20}{7}[/tex]
Hence, force exerted by mass of 2 kg on a mass of 5 kg will be calculated as follows.
[tex]20 - F_{1} = 5 \times \frac{20}{7}[/tex]
[tex]F_{1}[/tex] = 5.714 N
Thus, we can conclude that magnitude of the force that the 5.00-kg block exerts on the 2.00-kg block is 5.714 N.