# Calculating Momentum with Constant Force

• Alucard2487
In summary: There are many good online resources for physics, including Khan Academy, HyperPhysics, and MIT OpenCourseWare. It's also helpful to search for specific topics on YouTube to find videos that explain them in an engaging way.
Alucard2487

## Homework Statement

At a certain instant a particle (mass=0.5 kg) is moving in the +x direction with velocity 14 m/s. During the next 0.15 seconds a constant force acts on the particle, with Fx= −8 N and Fy= Fz = 0 N. What is the magnitude of the momentum of the particle (in kg*m/s) at the end of this 0.15 second interval?

## Homework Equations

pf = pi + Fnet*deltat

## The Attempt at a Solution

I am at a complete lose as to what to do. I think I have to add the velocity and the Fx together. After that, I have no idea.

Hi Alucard2487! Welcome to PF!
Alucard2487 said:
… I think I have to add the velocity and the Fx together. After that, I have no idea.

i] you can only add things of the same srot, eg two velocities or two momentums or two forces …

you can't add a velocity to a force

ii] force is rate of change of momentum, so how much and in which direction does the given force change the momentum? and what was the original momentum?

show us what you get

Alucard2487 said:

## Homework Statement

At a certain instant a particle (mass=0.5 kg) is moving in the +x direction with velocity 14 m/s. During the next 0.15 seconds a constant force acts on the particle, with Fx= −8 N and Fy= Fz = 0 N. What is the magnitude of the momentum of the particle (in kg*m/s) at the end of this 0.15 second interval?

## Homework Equations

pf = pi + Fnet*deltat

## The Attempt at a Solution

I am at a complete lose as to what to do. I think I have to add the velocity and the Fx together. After that, I have no idea.

Your relevant equation is indeed relevant.

you are after pf [pf]

You can calculate pi [pi]
You were given Fnet [Fnet]
You were given deltat [Δt]

I was also wondering if there is a good youtube channel that I could watch. My professor doesn't have a good grasp on the English language, so it's hard to understand her.

I figured it out. What I did was this: .5kg(14)+(-8)(.15). I ended up with 5.8kg*m/s which was the correct answer.

Alucard2487 said:
I figured it out. What I did was this: .5kg(14)+(-8)(.15). I ended up with 5.8kg*m/s which was the correct answer.

Alucard2487 said:
I was also wondering if there is a good youtube channel that I could watch.

probably better to find a good online book

Any recommendations? We use "Matter and Interactions" in class and I find the book to be a bit dull.

## What is the momentum principle?

The momentum principle, also known as the law of conservation of momentum, states that in a closed system, the total momentum before a collision or interaction is equal to the total momentum after the collision or interaction.

## How is momentum defined?

Momentum is defined as the product of an object's mass and velocity. It is a vector quantity, meaning it has both magnitude and direction.

## What is the relationship between force and momentum?

The relationship between force and momentum is described by Newton's second law of motion, which states that the net force acting on an object is equal to the change in momentum of the object over time.

## What are some real-life examples of the momentum principle in action?

Some examples of the momentum principle in action include a car crash, a game of billiards, and a rocket launch. In each of these scenarios, the total momentum before the event is equal to the total momentum after the event.

## How does the momentum principle apply to daily life?

The momentum principle can help us understand and predict the outcomes of interactions between objects. It is also important in designing and engineering various machines and devices, such as cars, airplanes, and sports equipment.

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