Mass = 20kg
K.E = 40Joules.
velocity = ?
K.E = 1/2mV²
40 = (1/2)*20V²
40 = 10V²
V² = 4
V = 2m/s
Therefore, speed= 2m/s...

**Calculating the Speed of a Moving Body**

To calculate the speed of a moving body, we need to use the formula for kinetic energy. Kinetic energy is the energy possessed by an object due to its motion. The formula for kinetic energy is:

Kinetic Energy (KE) = 1/2 * mass * speed^2

Given:
Mass (m) = 20 kg
Kinetic Energy (KE) = 40 J

We can rearrange the formula to solve for speed:

Speed (v) = √(2 * KE / mass)

**Substituting the given values into the formula:**

Speed (v) = √(2 * 40 J / 20 kg)

Simplifying the equation:

Speed (v) = √(80 J / 20 kg)

Speed (v) = √4 m^2/s^2

Taking the square root:

Speed (v) = 2 m/s

Hence, the speed of the moving body is 2 m/s.

**Explanation:**

When an object is in motion, it possesses kinetic energy. The amount of kinetic energy depends on the mass and speed of the object. In this case, we are given the mass of the body as 20 kg and the kinetic energy as 40 J.

By using the formula for kinetic energy and rearranging it to solve for speed, we can substitute the given values to calculate the speed of the moving body. The formula for speed involves taking the square root of the ratio of twice the kinetic energy to the mass of the object.

After substituting the values and simplifying the equation, we find that the speed of the moving body is 2 m/s.

This means that the body is moving at a rate of 2 meters per second.