Question

PHYS 113 Test I Take Home Problems To be turned in with Test 1. Please show all work on these sheets in a neat, organized manner You may use the back of the sheets or attach additional sheets if needed A small ball (like we used in the demos on the first day of class) has a mass 60 x 10 kg and hangs from a string A piece of plastic is rubbed with fur and then touched to the ball, transferring a charge of -1.50 nC to the ball The ball is then placed into a horizontal uniform electric field, causing the ball to swing out to the left and come to a stable position at an angle of 123 to the left of L. 123 vertical What is the magnitude and direction of the electric field?

if anyone can explain this in algebra physics that'd be great. can't get the right answer. thanks

Answer 1

Given

Mass of ball m = 6.0 * 10^-6 kg

Charge on ball transferred q= -1.50 nC

As the ball is placed in uniform electric field , ball with string gets deflected making an angle 12.3° with the vertical at stable position.

Free body diagram of ball is shown below at stable position

Now calculate Electrostatic force Fe by balancing forces in X and Y direction.

Teose- m9 ん Dwdm ( and i Le iven near 순 12.3。 rm Cs 2.3 Fe

Now as we know Fe = q*E

Find E from above relation

​​​​​As the calculated value of E has positive Magnitude . It can be concluded that it's direction is towards positive X axis.

Magnitutude of Electric field = 8546.93 NC^-1