Given:

Mass of bullet, m = 20 g = 0.02 kg

Distance between two points, d = 30 m

Time interval, t = 4 s


Finding:

Kinetic energy of bullet


Formula:

The formula to calculate kinetic energy is:

Kinetic Energy = (1/2) * mass * velocity^2


Calculations:

The velocity of the bullet can be calculated using the formula:

Velocity = Distance / Time

Velocity = 30 / 4 = 7.5 m/s


Plugging the values in the formula for kinetic energy:

Kinetic Energy = (1/2) * mass * velocity^2

Kinetic Energy = (1/2) * 0.02 * 7.5^2

Kinetic Energy = 0.84 J


Therefore, the kinetic energy of the bullet is 0.84 J.


Explanation:

Kinetic energy is the energy of motion of an object. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity. In this problem, the bullet is moving with constant speed, so we can use the formula for kinetic energy to find the energy of the bullet.

To find the velocity of the bullet, we used the formula velocity = distance / time. The distance between the two points is given as 30 m and the time interval is given as 4 s. Plugging these values in the formula, we get the velocity of the bullet as 7.5 m/s.

Finally, we plug the mass and velocity of the bullet in the formula for kinetic energy to get the answer. The mass of the bullet is given as 20 g which we convert to kilograms by dividing by 1000. Plugging all the values in the formula, we get the kinetic energy of the bullet as 0.84 J.

It is simple.

Use the formula of velocity,
V = S /T
V = 30/4.

Then use the formula of K.E.

K.E = 1/2 mv^2.

(Put the value of the quality in their standard form or according to the option)

After putting the value u will get the answer.