A 50µC charged sphere of mass 0.050kg is 2.0m away from a -30 µC charged sphere. The 50 µC charged sphere is moved to a point 1.2m away. What is the change in energy of this sphere ?

To find the change in energy of a charged sphere, we need to calculate the potential energy before and after the movement.

The formula for the potential energy of a charged sphere is given by:

U = (k * q1 * q2) / r

where U is the potential energy, k is the electrostatic constant (k = 9 * 10^9 N m^2/C^2), q1 and q2 are the charges of the spheres, and r is the distance between the spheres.

First, let's calculate the potential energy before the movement.

q1 = 50 µC = 50 * 10^-6 C
q2 = -30 µC = -30 * 10^-6 C
r1 = 2.0 m

U1 = (k * q1 * q2) / r1

Plugging the values into the formula:

U1 = (9 * 10^9 N m^2/C^2) * (50 * 10^-6 C) * (-30 * 10^-6 C) / 2.0 m

Now, let's calculate the potential energy after the movement.

r2 = 1.2 m

U2 = (k * q1 * q2) / r2

Plugging the values into the formula:

U2 = (9 * 10^9 N m^2/C^2) * (50 * 10^-6 C) * (-30 * 10^-6 C) / 1.2 m

Finally, we can find the change in energy by subtracting the initial potential energy from the final potential energy:

ΔU = U2 - U1

Now, you can plug the values into the equations to find the change in energy for the charged sphere.