Answer: option A. strong nuclear force.
Explanation:
The diagram shows the subatomic particles inside the nucelous: protons and neutrons.
As you know, the protons are positively charged partilces inside the nucleous.
Being those particles charged with the same kind of charge they experiment electrostatic repulsion. So, how do you explain that they can stand together in such small space as it is the nucleous?
The responsible of keeping the subatomic particles together is the so called strong nuclear force.
Strong nuclear force or simply strong force is one of the four fundamental interactions or forces: i) gravitational, ii) electromagnetic, iii) weak nuclear force, and iv) strong nuclear force.
Strong nuclear force is the strongest force of nature and acts only in short distances as those inside the nucleous and is responsible for both the atraction among quarks and the atraction among protons to bind them together inside the atomic nucleous.
Speed is the distance travelled by an object whereas velocity is distance travelled by an object per unit time in a given direction.
Explanation:
a) I = V / R
1.70 = 115 / R
R = 115 / 1.70
R = 67.647
R = 67.65 ohms
Therefore, equivalent resistance is 67.65 ohms
b) Equivalent resistance of circuit from above sum is 67.65 ohms
Given resistance of each bulb is 1.50 ohms
Number bulbs = Equivalent resistance / Resistance of each bulb
= 67.65 / 1.50
= 45