After running PhET simulations on electrostatic forces with a previous knowledge on universal law of gravitation, you may conclude 1.Gravitational attraction (FG) between two protons can't be compared with the electrostatic repulsion (Fq) as one is based on inertial property and the other is based on electrical properties 2. Gravitational attraction (FG) between two protons and the electrostatic repulsion (Fq) may be considered as an action-reaction pair. 3. Relative to the gravitational attraction (FG) between two protons, the electrostatic repulsion (Fq) is much stronger 4. Relative to the gravitational attraction (FG) between two protons, the electrostatic repulsion (Fq) is much weaker

Coulomb’s law tells us that the electrostatic force between two charged objects can be calculated by: ?= ??1?2/?^2Where k is a constant with a value of 8.99x109 Nm2/C2; ?1 and ?2 are the charges of the two particles (1.602x10-19 C), and r is the distance between the two particles. The force is attractive if the charges of the two particles is opposite (one’s positive and one’s negative) and repulsive if the charges have the same charge (both positive or both negative). Calculate the electrostatic force on proton #1 from the other two protons.Will the gravitational force between the protons be attractive or repulsive? What about the electrostatic force? Which has the larger magnitude, the electrostatic force or the gravitational force? Can the electrostatic and gravitational forces alone create a stable Lithium nucleus?

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1. When point charges q = +8 4 µC and q2 = + 5,6µC are brought near each other, each experiences a repulsive force of magnitude 0.77. N. Determine the distance between the two charges. [ Given Data, Coulomb's Constant, Ke = 8.99X10 Nm2/C21 The distance between the two charges = m. [2 marks] 2.An electric field of 250000 N/C points due west at a certain spot. What are the magnitude and direction of the force that acts on a charge 7:0HC at this spot? The magnitude of the force = N and direction = from the charge. [2 marks)

Two identically charged particles separated by 5 cm repel each other with a force of 80 mN. Determine the repulsive force if the separation distance changes to 20 cm.

3) Skid Infinite Black Pit Mitch Skid of 40 kg and Mitch of 60 kg are standing on ice on opposite sides of an infinite black pit. They are each carrying neutral massless spheres while standing 8 m apart. Suppose that 3.0 x 10¹5 electrons are removed from one sphere and placed on the other. (a) Calculate the magnitude of the electrostatic force on each sphere. Are the forces the same or different? Explain. (b) Calculate the magnitude of the accelerations for Skid and Mitch at the moment they are 8 m apart. Are they the same or different? Explain. (c) As Skid and Mitch move closer together do their accelerations increase, decrease, or remain the same? Explain.

There are 2 kinds of electric charge: positive and negative. What are 2 examples of how we make use of charged particles. Explain your example.

1. Consider four 1 Coulomb charges, arranged in a square, 1m on a side. a) What is the energy of a 1 Coulomb charge in the centre of the square? b) For fun (for some definitions of fun) express this quantity in terms of the energy released by the explosion of a ton of TNT. (What this really tells us is that a Coulomb is large amount of charge.)

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Please explain