# Force with kinetic energy question

• XxMuDvAyNexX
In summary, the conversation discusses how to calculate the force exerted on a 2.5-g bullet that slows down and penetrates a 12 cm distance into a tree after traveling at 350 m/s. The suggested method is to use the equation v^2 = u^2 + 2as to calculate the acceleration, and then use the formula F=ma to determine the force. The final answer is determined to be -1276.04 N.
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[SOLVED] Force with kinetic energy question

A 2.5-g bullet traveling at 350 m/s hits a tree and slows uniformly to a stop while penetrating a distance of 12 cm into the tree's truck. What force was exerted on the bullet in bringing it to a rest?

Not sure on this one. I know to find to the kinetic energy would be KE=1/2mv^2. I'm not sure if that is needed though. And to find force would be F=W/D or F=MA.

So far I only have KE=153.125 using the equation above. I plugged in 1/2(.0025kg)(350m/sec)^2. Now I'm not sure what to do. I want to try to find W since it includes distance. I don't know if there is an equation to find work by using only M,V,and X. Hmm..I'm confused now.

You know the initial and final velocity, and you know the distance over which the acceleration took place. From these three you can calculate the acceleration with $$v^{2} = u^{2} + 2as$$.

From there you can determine the force exerted on the bullet.

You're doing fine by calculating the KE. How does work done (FD) relate to the change in KE?

They are equal aren't they? W=K-Ko

Ahh I think figured it out. The W would be equal to =-153.125J. Then I would just use F=W/D or F=-153.125 J/.12m and that comes out to be...-1276.04. Is that correct?

Yep, that's right.

Thank you again!

## What is force with kinetic energy?

Force with kinetic energy is a type of energy that an object possesses due to its motion. It is dependent on the mass and velocity of an object, and is measured in joules.

## What is the relationship between force and kinetic energy?

The relationship between force and kinetic energy is directly proportional. This means that as the force acting on an object increases, its kinetic energy will also increase.

## How is force with kinetic energy calculated?

Force with kinetic energy is calculated by multiplying the mass of an object by its velocity squared, and dividing by 2. The formula for force with kinetic energy is KE = 1/2 * mv^2.

## What are some examples of force with kinetic energy?

Some examples of force with kinetic energy include a moving car, a flying airplane, and a swinging pendulum. Essentially, any object that is in motion has force with kinetic energy.

## Why is understanding force with kinetic energy important?

Understanding force with kinetic energy is important because it helps us understand how objects move and interact with each other. It is also a fundamental concept in physics and is crucial in fields such as engineering and mechanics.

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