Monday

September 22, 2014

September 22, 2014

Posted by **Kevin** on Wednesday, September 13, 2006 at 5:52pm.

1) A point charge of -0.90 microC is fixed to one corner of a square. An identical charge is fixed to the diagonally opposite corner. A point charge q is fixed to each of the remaining corners. The net force acting on either of the charges q is zero. Find the magnitude of q.

- i keep getting 3.6 micro C

2) A proton is moving parallel to a uniform electric field. The electric field accelerates the proton and increases its linear momentum to 8.6 x 10^-23 kg·m/s from 2.4 x 10^-23 kg·m/s in a time of 5.7 x 10^-6 s. What is the magnitude of the electric field?

3) A uniform electric field has a magnitude of 3.1 x 10^3 N/C. In a vacuum, a proton begins with a speed of 2.5 x 10^4 m/s and moves in the direction of this field. Find the speed of the proton after it has moved a distance of 1.5 mm.

Edit - Question One answer was found, only need help on question 2 and 3 now

1) A point charge of -0.90 microC is fixed to one corner of a square. An identical charge is fixed to the diagonally opposite corner. A point charge q is fixed to each of the remaining corners. The net force acting on either of the charges q is zero. Find the magnitude of q.

- i keep getting 3.6 micro C

Find the repulsive force from the opposite corner. Then find the repulsive attractive force from one q IN THE DIRECTION of the diagonal kq(-.90)/s^2 *cos45 The other corner has an equal force, so the NET force on the .90C charge is

.90^2/2s^2 -.90q/s^2 *1.414=0

or .90/2=q*1.414*2

or q= check my work.

2) A proton is moving parallel to a uniform electric field. The electric field accelerates the proton and increases its linear momentum to 8.6 x 10^-23 kgï¿½m/s from 2.4 x 10^-23 kgï¿½m/s in a time of 5.7 x 10^-6 s. What is the magnitude of the electric field?

The force will change with velocity, so calculus will be requrired. Change the changes in momentum to changes in velocty (you know the mass of the proton).

You can determine the accelation of the proton from the changes in velocity/time.

Forceelectric= mass*a

Then, knowing the forceelectric, use the electric field-velocity equation to find E.

3) A uniform electric field has a magnitude of 3.1 x 10^3 N/C. In a vacuum, a proton begins with a speed of 2.5 x 10^4 m/s and moves in the direction of this field. Find the speed of the proton after it has moved a distance of 1.5 mm.

Find F=Eq=ma

From a, finalvelocity^2=initialvelocity^ + 2a*distance

i tried the method you suggested for #2 and #3, but the answer are not correct. the values i got for #2 is 1.355268 x 10^-25 and #3 25017.8105

**Answer this Question**

**Related Questions**

Algebra - Hi, would it be possible for a bit of guidance on the following ...

thx 4 the help roger - thx 4 the help i got the steps You're welcome and I'm ...

Math - I am stuck on this question. Could someone work it out. Id appreciate it...

algebra 1 - in the equation 5x+y=-1,m= I will be happy to critique your work on ...

General - Please understand that I am not upset with anyone or whatever I just ...

english - Which of the following is not true of an epic? a. it is a long ...

math - I have a couple of math questions that i cant seem to get to work out. ...

Physics help! - I need to know all of the equations for WORK problems (Physics...

Basic Algebra - I have to solve the following equation and check my work. Not ...

College Math II - Solve by any method. a^4 – 5a^2 + 4 = 0 I am having problems ...