# Solving Physics Question: Momentum Change of 0.42 kg Ball

• draconicspectre
In summary, the magnitude of the change in linear momentum of the ball can be calculated by subtracting the final momentum from the initial momentum, which is given by mv2-mv1. This value should be used to find the correct answer.
draconicspectre
A 0.42 kg ball is moving horizontally with a speed of 5.5 m/s when it strikes a vertical wall. The ball rebounds with a speed of 2.0 m/s. What is the magnitude of the change in linear momentum of the ball?

Might seem like a simple problem, but everytime i input an answer into it, it says I am wrong, can neone help?

draconicspectre said:
A 0.42 kg ball is moving horizontally with a speed of 5.5 m/s when it strikes a vertical wall. The ball rebounds with a speed of 2.0 m/s. What is the magnitude of the change in linear momentum of the ball?

Might seem like a simple problem, but everytime i input an answer into it, it says I am wrong, can neone help?

Since the change in linear momentum is a vector given by (mv2-mv1)i, its magnitude is the square root of (mv2-mv1)^2, which equals mv2-mv1. This should work.

I would approach this problem by first understanding the concept of linear momentum. Linear momentum is defined as the product of an object's mass and its velocity. In this case, the 0.42 kg ball has an initial momentum of 0.42 x 5.5 = 2.31 kg*m/s in the horizontal direction before it strikes the wall.

After the collision, the ball rebounds with a speed of 2.0 m/s in the opposite direction. This means that its final momentum is 0.42 x (-2.0) = -0.84 kg*m/s. The negative sign indicates that the ball's momentum has changed direction.

To find the magnitude of the change in linear momentum, we can simply calculate the difference between the initial and final momenta. This would be 2.31 - (-0.84) = 3.15 kg*m/s. This means that the magnitude of the change in linear momentum of the ball is 3.15 kg*m/s.

It is important to note that the direction of the change in momentum is opposite to the initial momentum, as the ball is rebounding in the opposite direction. This concept is in accordance with the law of conservation of momentum, which states that the total momentum of a system remains constant unless an external force acts upon it.

In conclusion, the magnitude of the change in linear momentum of the 0.42 kg ball is 3.15 kg*m/s in the opposite direction. It is crucial to understand the concepts of momentum and conservation of momentum in order to solve such physics problems accurately.

## 1. What is momentum?

Momentum is a measure of an object's motion, calculated by multiplying its mass by its velocity.

## 2. How do you calculate momentum?

Momentum (p) is calculated by multiplying an object's mass (m) by its velocity (v): p = m x v.

## 3. What is the momentum change of a 0.42 kg ball?

The momentum change of the ball will depend on its initial and final velocities. If we assume the initial velocity is zero, the momentum change is simply equal to the final momentum, which can be calculated using the equation p = m x v.

## 4. How do you solve for the velocity of the ball?

To solve for the velocity of the ball, we can rearrange the momentum equation to v = p/m. Plug in the known values for mass and momentum to find the velocity.

## 5. What is the unit for momentum?

The unit for momentum is kilogram-meters per second (kg·m/s).

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