# Can you confirm a simple Physics Velocity Question?

• pinnacleprouk
In summary, two objects with masses of 6kg and 8kg, moving at velocities of 5m/s and 8m/s respectively, collide and join together, moving in the same original direction. The common velocity of the joined objects can be calculated by adding the initial momentums of each mass. The correct calculation is 5x6 + 8x8 = 14V, resulting in a common velocity of 6.71m/s.
pinnacleprouk

## Homework Statement

Object a Mass 6kg moving velocity 5m/s is followed by a second object mass 8kg velocity 8m/s in the same straight line.

If the two objects are joined together after collision and move in the original direction, calculate heir common velocity.

## The Attempt at a Solution

Now have either:

6x5 - 8x8 = 14V

-34 = 14V

-34/14 = V

V = -2.42m/s

or 5x6 + 8x8 = 14V

94 = 14V

94/14 = V

V = 6.71m/s

Which one is right?

The second one is right because both of the objects are moving in the same direction hence you would ADD the initial momentum of each mass.

I cannot confirm the accuracy of your calculations without knowing the specific context and assumptions made in the problem. However, I can provide some guidance on how to approach this type of physics question. In order to calculate the common velocity of the two objects after collision, you need to apply the principle of conservation of momentum. This principle states that the total momentum of a closed system (in this case, the two objects) remains constant before and after a collision. Therefore, you can set up an equation using the initial momentum of the two objects (mass x velocity) and the final momentum of the combined object (mass x common velocity). Solving this equation will give you the correct answer for the common velocity. It is important to note that the negative sign in your first attempt indicates that the velocity is in the opposite direction to the initial velocity of the first object. I would recommend double-checking your calculations and making sure you are using the correct units (m/s) for velocity. Additionally, it may be helpful to draw a diagram to visualize the situation and make sure your calculations align with the laws of physics.

## 1. What is velocity in physics?

Velocity is defined as the rate of change of an object's position with respect to time. It is a vector quantity, which means it has both magnitude (speed) and direction.

## 2. How is velocity calculated in physics?

Velocity is calculated by dividing the change in position (displacement) by the change in time. This can be represented by the equation v = Δx/Δt, where v is velocity, Δx is displacement, and Δt is change in time.

## 3. What is the difference between velocity and speed in physics?

Velocity and speed are often used interchangeably in everyday language, but they have different definitions in physics. While velocity is a vector quantity that includes direction, speed is a scalar quantity that only includes magnitude.

## 4. How does velocity affect an object's motion?

The velocity of an object affects its motion in two ways: speed and direction. A change in velocity (either in speed or direction) will result in a change in the object's motion, such as acceleration, deceleration, or change in direction.

## 5. Can velocity be negative in physics?

Yes, velocity can be positive or negative in physics. A positive velocity indicates that an object is moving in the positive direction, while a negative velocity indicates that an object is moving in the negative direction. This is determined by the direction of the object's displacement.

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