Answer:
209.53 N
Explanation:
To find the force on the third charge you use the Coulomb formula:

k: Coulomb's constant = 8.98*10^9 Nm^2/C^2
The force on the third charge is the contribution of the force between the third charge and the other ones:

By taking into account that the third charge is at the middle of the distance between charge 1 and charge 2 you have r = 0.12m/2 = 0.06m
Furthermore, you take into account that the first charge repels the third charge and the second charge attracts the third charge.
By replacing you have:
![F=k\frac{q_1q_3}{r^2}+k\frac{q_2q_3}{r^2}\\\\F=\frac{k}{r^2}q_3[q_1+q_2]\\\\F=\frac{(8.98*10^9Nm^2/C^2)(4*10^{-6}C)}{(0.06m)^2}[8*10^{-6}C+13*10^{-6}C]\\\\F=209.53\ N](https://tex.z-dn.net/?f=F%3Dk%5Cfrac%7Bq_1q_3%7D%7Br%5E2%7D%2Bk%5Cfrac%7Bq_2q_3%7D%7Br%5E2%7D%5C%5C%5C%5CF%3D%5Cfrac%7Bk%7D%7Br%5E2%7Dq_3%5Bq_1%2Bq_2%5D%5C%5C%5C%5CF%3D%5Cfrac%7B%288.98%2A10%5E9Nm%5E2%2FC%5E2%29%284%2A10%5E%7B-6%7DC%29%7D%7B%280.06m%29%5E2%7D%5B8%2A10%5E%7B-6%7DC%2B13%2A10%5E%7B-6%7DC%5D%5C%5C%5C%5CF%3D209.53%5C%20N)
Hence, the force between on the third charge is 209.53 N
Answer: 
Explanation:
Given
Mass of receiver 
Running at a speed of 
time taken to stop 
We know, impulse imparted is given by

Thus, 1200 N is needed to stop the receiver.
Here's a picture of Kinematic formulas
The kinematic formulas are a set of formulas that relate the five kinematic variables listed below.
Δx - Displacement
t - Time interval
v0 - Initial velocity
v- Final velocity
a - Constant acceleration
The frequency of oscillation on the frictionless floor is 28 Hz.
<h3>
Frequency of the simple harmonic motion</h3>
The frequency of the oscillation is calculated as follows;
f = (1/2π)(√k/m)
where;
- k is the spring constant
- m is mass of the block
f = (1/2π)(√7580/0.245)
f = 28 Hz
Thus, the frequency of oscillation on the frictionless floor is 28 Hz.
Learn more about frequency here: brainly.com/question/10728818
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