please tell me if thsi si correct

Two equal charges are separated by 3.7 * 10^-10 m. the force between the charges has a magnitude of 2.37 * 10^-3 N. What is the magnitude of q on the changes?

f=1/4pi Er * q^2/r^2

2.37 * 10^-3 = 9*10^9 * q^2
______________
(3.7 * 10^-10)^2

3.61 * 10^-32= q^2
q= 1.8 * 10^-16
is that correct?

What is the resistance of a resistor if the potential difference across the resistor is 4.0 V when a current of 10.0 A flows through the resistor?

R=V/I= 4/10

R=0.4 ohms

is this done correctly

thanks

For the first question, your calculations are correct. The magnitude of q on the charges is indeed 1.8 * 10^-16 C.

For the second question, your calculations are also correct. The resistance of the resistor is 0.4 ohms when a potential difference of 4.0 V is applied with a current of 10.0 A flowing through it.

Well done!

Yes, you have solved both problems correctly.

For the first problem, you used the formula for the force between two charges, which is given by F = (1/4πε₀) * (q₁q₂/r²), where ε₀ is the permittivity of free space. Rearranging the formula to solve for q₁ or q₂, you get q₁ = √(F * r² / (q₂ * 9 * 10^9)). Plugging in the given values, you correctly found that q₁ (and q₂) has a magnitude of 1.8 * 10^-16 C.

For the second problem, you correctly used Ohm's Law, which states that the resistance (R) is equal to the potential difference (V) divided by the current (I). Plugging in the given values, you correctly found that the resistance is 0.4 ohms.