Let F be the magnitude of the force. The impulse of this force while the ball is in contact with the wall is
Ft = F (0.0210 s)
and this impulse is equal to the change in the ball's momentum,
m ∆v = (1.30 kg) (6.50 m/s - (-10.5 m/s)) = (1.30 kg) (17.0 m/s)
Solve for F :
F (0.0210 s) = (1.30 kg) (17.0 m/s)
F = (1.30 kg) (17.0 m/s) / (0.0210 s)
F ≈ 1050 N
Answer:
(a): 
(b): 
Explanation:
<u>Given:</u>
- Charge on one sphere,

- Charge on second sphere,

- Separation between the spheres,

Part (a):
According to Coulomb's law, the magnitude of the electrostatic force of interaction between two static point charges is given by

where,
k is called the Coulomb's constant, whose value is 
From Newton's third law of motion, both the spheres experience same force.
Therefore, the magnitude of the force that each sphere experiences is given by

The negative sign shows that the force is attractive in nature.
Part (b):
The spheres are identical in size. When the spheres are brought in contact with each other then the charge on both the spheres redistributes in such a way that the net charge on both the spheres distributed equally on both.
Total charge on both the spheres, 
The new charges on both the spheres are equal and given by

The magnitude of the force that each sphere now experiences is given by
I = V/Z
V = voltage, I = current, Z = impedance
First let's find the total impedance of the circuit.
The impedance of the resistor is:
= R
R = resistance
Given values:
R = 1200Ω
Plug in:
= 1200Ω
The impedance of the inductor is:
= j2πfL
f = source frequency, L = inductance
Given values:
f = 59Hz, L = 2.4H
Plug in:
= j2π(59)(2.4) = j889.7Ω
Add up the individual impedances to get the Z, and convert Z to polar form:
Z =
+ 
Z = 1200 + j889.7
Z = 1494∠36.55°Ω
I = V/Z
Given values:
V = 170∠0°V (assume 0 initial phase)
Z = 1494∠36.55°Ω
I = 170∠0°/1494∠36.55°Ω
I = 0.1138∠-36.55°A
Round the magnitude of I to 2 significant figures and now you have your maximum current:
I = 0.11A
A and c should be the answer