# Finding kinetic energy consevered after collision

• qwerty5050
In summary, two cars of equal mass traveling in opposite directions on a wet and slippery road collide and lock together, moving off in an easterly direction at 5 m/s. The initial velocities of the cars were 20 m/s and 30 m/s, with no braking before the collision. The fraction of initial kinetic energy conserved during the collision can be calculated using the equation Ek=1/2mv^2. To determine the fraction, we need to consider any relevant laws or equations that may apply, such as the conservation of momentum or the conservation of energy. It is important to think critically and consider all possible factors when attempting to solve this problem.
qwerty5050

## Homework Statement

2 cars of equal mass and traveling in opposite directions on a wet and slippery road collide and lock together after impact. Neither car brakes before the collision. The tangled wreck moves off in an easterly direction at 5 m/s immediately after the collision. if one car was traveling due west at 20 m/s immediately before the collision and the other at 30 m/s.
What fraction of the initial kinetic energy as conserved during the collision?

## Homework Equations

Ek=1/2mv^2 - this is the only equation i know that has to do with kinetic energy

## The Attempt at a Solution

I have no idea what i have to do

Last edited:
qwerty5050 said:
I have no idea what i have to do
Start by listing equations that you think may be relevant. Perhaps that will trigger an idea or two for an attempt.

gneill said:
Start by listing equations that you think may be relevant. Perhaps that will trigger an idea or two for an attempt.
I've been doing that but I'm still not sure what to do.

qwerty5050 said:
I've been doing that but I'm still not sure what to do.
Hmm. You haven't posted any, so we can't tell if you're on the right track or not.

The topic is kinetic energy. What equations do you know pertaining to kinetic energy?

Try to think of things that remain constant during the given collision. Any law you know that might apply. Think!

## 1. What is kinetic energy conservation?

Kinetic energy conservation is a principle in physics that states that the total amount of kinetic energy in a closed system remains constant over time. This means that in a collision between two objects, the total kinetic energy before and after the collision should be the same.

## 2. How is kinetic energy conserved in a collision?

In a collision, kinetic energy is conserved by following the laws of conservation of energy and momentum. This means that the total energy of the system, including both kinetic and potential energy, must remain constant. The momentum of the objects before and after the collision must also be equal.

## 3. What factors can affect the conservation of kinetic energy in a collision?

The conservation of kinetic energy in a collision can be affected by factors such as the mass and velocity of the objects involved, the type of collision (elastic or inelastic), and external forces acting on the system. Friction and air resistance can also influence the conservation of kinetic energy.

## 4. How can kinetic energy conservation be calculated in a collision?

The conservation of kinetic energy in a collision can be calculated by using the formula KE = 1/2mv^2, where KE is kinetic energy, m is the mass of the object, and v is the velocity. This formula can be applied to both objects involved in the collision to determine the total kinetic energy before and after the collision.

## 5. Why is kinetic energy conservation important in collisions?

Kinetic energy conservation is important in collisions because it helps us understand and predict the behavior of objects during a collision. It also allows us to calculate the speed and direction of the objects after the collision based on the initial conditions. Additionally, the conservation of kinetic energy is a fundamental principle in physics that helps us explain and analyze many other phenomena in the natural world.

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