Determining magnitude of forces on metal balls

In summary: Just make sure you use the correct charges and distances for each scenario. In summary, three tiny metal balls are arranged in a straight line, with the middle ball having a positive charge and the two outside balls having a negative charge. The absolute value of the charge on each ball is 1.79 μCoulombs. Using Coulomb's law, the magnitude of the attractive force on either outside ball due to the positively-charged middle ball can be calculated by using the formula F = k(q_a)(q_b)/r^2, where k = 8.99e9 N*m^2/C^2 and q_a = -1.79e-6 C, q_b = 1.79e-6
  • #1
kasmit18
2
0
Three tiny charged metal balls are arranged on a straight line. The middle ball is positively charged and the two outside balls are negatively charged. The two outside balls are separated by 20 cm and the middle ball is exactly halfway in between.The absolute value of the charge on each ball is the same, 1.79 μCoulombs

(a) What is the magnitude of the attractive force on either outside ball due ONLY to the positively-charged middle ball?
(b) What is the magnitude of the repulsive force on either outside ball due ONLY to the other outside ball?
(c) What is the magnitude of the net force on either outside ball?




Please help?
 
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  • #2
look up in your book "Coulomb's law". Don't forget to convert your cm to meters, and your microcoulombs to coulombs.
 
  • #3
F = k(q_a)(q_b)/r^2

I know so far I should set it up like..

F = 8.99E9

but I don't know what the other terms apply to...help?
 
  • #4
k=8.99e9

For part (a):
q_a is the charge of one of the outside balls (-1.79 micro Coulombs)
q_b is the charge of the inside ball (1.79 micro Coulombs)
r is the distance between them (20 cm)

if you use 8.99e9 for k, the formula is expecting Coulombs, not microcoulombs, and meters, not centimeters. So convert these. Also, look up the units for k and include them. Then you can cancel your units. You know force has units of Newtons, which is kg * m/s^2, so your units should cancel to that.

Parts (b) and (c) are similar.
 

FAQ: Determining magnitude of forces on metal balls

1. What is the purpose of determining the magnitude of forces on metal balls?

The purpose of determining the magnitude of forces on metal balls is to understand the forces acting on the balls in a particular scenario. This information can be used to analyze the behavior of the balls and predict their motion.

2. How is the magnitude of forces on metal balls measured?

The magnitude of forces on metal balls can be measured using various methods such as force sensors, strain gauges, or by calculating the acceleration of the balls using Newton's second law of motion.

3. What factors can affect the magnitude of forces on metal balls?

The magnitude of forces on metal balls can be affected by various factors such as the mass and velocity of the balls, the surface they are rolling on, and any external forces acting on them.

4. Why is it important to consider the direction of forces when determining their magnitude on metal balls?

The direction of forces is important because it affects the resulting motion of the balls. For example, if a force is applied in the opposite direction of the ball's motion, it will slow down or stop the ball.

5. How can the magnitude of forces on metal balls be used in real-world applications?

The magnitude of forces on metal balls can be used in a variety of real-world applications such as designing sports equipment, analyzing collisions in car accidents, and predicting the motion of objects in engineering projects.

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