**The net force acting on the center O is 4.495 X 10⁹ N**

<u>**Explanation:**</u>

Given:

Charge-

q₁ = 4C

q₂ = 3C

q₃ = -5C

q₄ = 2C

q₅ = 1C

Side of the square = 4cm

Net force acting on the center, F = ?

Length of the side of the square is 4cm

The length of the diagonal will be 4√2

The length of half diagonal = 4√2 / 2 = 2√2

Force acting on the center of the square is:

Here, k is coulomb's constant and the value is

k = 8.99 x 10⁹ N m2 / C2

On substituting the value, we get:

**Therefore, the net force acting on the center O is 4.495 X 10⁹ N**

**Answer:**

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**Explanation:**

**Answer:**

The first and the last answer

Given: Mass m = 400 Kg; Height h = 3 m; g = 10 m/s²

Required: Work = ?

Formula: Work = Force x distance F = ma a = g F = mg

W = fd

W = mgh

W = (400 Kg)(10 m/s²)( 3 m)

W = 12,000 Kg.m²/s²

W = 12,000 J

**Answer:**

Answer to #1, is D.

**Explanation:**

The theory of plate tectonics states that the Earth's solid outer crust, the lithosphere, is separated into plates that move over the asthenosphere, the molten upper portion of the mantle. This is also, a theory with the ring of fire.