# Electric field and speed - find acceleration.

• Mommy2KAR420
In summary, a proton starts from rest and accelerates in a uniform electric field of 640N/C. Its speed at a later time is 1.20x10^6m/s. Using the equation F = ma, we can find the magnitude of its acceleration, the time it takes to reach this speed, the distance it has moved, and its kinetic energy at the later time. Looking up the mass and charge of a proton will provide the necessary information for solving the problem.
Mommy2KAR420

## Homework Statement

A proton accelerates from rest in a uniform electric field of 640N/C. At some later time, its speed is 1.20x10^6m/s.
a) Find the magnitude of the acceleration of the proton.
b) How long does it take the proton to reach this speed?
c) How far has it moved in that interval?
d) What is its kinetic energy at the later time?

## The Attempt at a Solution

I think I can figure this problem out after knowing how to get started. I was confused as to how to start without having the mass. Any help?

You can look up the mass and charge of a proton.
Use F = ma.
Of course it is the electric field that causes the force, so put in the formula for that.

Thank you. I went outside for a break and had the revelation. I feel stupid now. I got the answer for each part now. I don't know why I wasn't thinking about looking up the charge and mass. Thanks again!

## 1. What is an electric field?

An electric field is a region in space where an electrically charged particle experiences a force. It is created by electrically charged objects and can be either positive or negative.

## 2. How is electric field related to speed?

The electric field can affect the speed of a charged particle by exerting a force on it. If the particle has a positive charge, it will accelerate in the direction of the electric field. If the particle has a negative charge, it will accelerate in the opposite direction.

## 3. How do you calculate the acceleration of a charged particle in an electric field?

The acceleration of a charged particle in an electric field can be calculated using the equation a = qE/m, where a is the acceleration, q is the charge of the particle, E is the electric field strength, and m is the mass of the particle.

## 4. Can the speed of a charged particle change in an electric field?

Yes, the speed of a charged particle can change in an electric field. If the particle is initially at rest and experiences a force from the electric field, it will accelerate and increase in speed. If the particle is already moving, the electric field can either increase or decrease its speed depending on the direction of the force.

## 5. How does the direction of the electric field affect the acceleration of a charged particle?

The direction of the electric field determines the direction of the force exerted on a charged particle. If the electric field is in the same direction as the particle's motion, it will accelerate the particle and increase its speed. If the electric field is in the opposite direction, it will decelerate the particle and decrease its speed.

• Introductory Physics Homework Help
Replies
9
Views
472
• Introductory Physics Homework Help
Replies
8
Views
532
• Introductory Physics Homework Help
Replies
9
Views
7K
• Introductory Physics Homework Help
Replies
5
Views
1K
• Introductory Physics Homework Help
Replies
12
Views
2K
• Introductory Physics Homework Help
Replies
4
Views
1K
• Introductory Physics Homework Help
Replies
16
Views
261
• Introductory Physics Homework Help
Replies
4
Views
450
• Introductory Physics Homework Help
Replies
2
Views
2K
• Introductory Physics Homework Help
Replies
1
Views
1K