# A bullet hits a wall with a velocity of 20m/s and penetrates it up to a distance of 5 cm. Find the deceleration of the bullet in the wall.

By Ritesh|Updated : November 12th, 2022

The deceleration of the bullet in the wall is -4000 m/s2. Steps to find the deceleration of the bullet in the wall:

Step 1: Given that

Final velocity v = 0,

The initial velocity of the bullet u = 20 m/s,

distance traveled, S = 5 cm = 0.05 m

Step 2: Now we have to find the negative acceleration

We have the 3rd equation of motion,

v2 - u2 = 2as

Substituting all the values

0 - (20)² = 2 × 0.05 × a

Or, 0.1 a = - 400

On simplifying we get

a = -400/0.1 = -4000 m/s2

Hence, the deceleration of the bullet in the wall is -4000 m/s2.

### Deceleration

• It is considered to be decelerating when the velocity change rate with respect to time is such that it continuously decreases.
• Retardation is another word for deceleration.
• Its unit is m/s2.
• For instance, a car is considered to be decelerating while it is slowing down.

Deceleration is the universal term for acceleration that occurs in the direction perpendicular to the direction of velocity. The pace is always slowed by acceleration. However, according to the chosen coordinate system, negative acceleration is just an acceleration in the other direction.

1. Deceleration is not the opposite of acceleration. There is no question that the velocity's temporal rate of change is positive.
2. Example: Negative acceleration can signify either growing or lowering speed, while deceleration always refers to slowing down or decreasing speed.

Summary:

## A bullet hits a wall with a velocity of 20m/s and penetrates it up to a distance of 5 cm. Find the deceleration of the bullet in the wall.

A bullet hits a wall with a velocity of 20m/s and penetrates it up to a distance of 5 cm. The deceleration of the bullet in the wall is -4000 m/s2. Deceleration is the process of reducing speed or the magnitude of velocity. In one-dimensional motion, deceleration is the acceleration that is opposed to velocity.