1)A charge of -3.90 ?C is located at the origin. A charge of 6.00 ?C is located

Question

1)A charge of -3.90 ?C is located at the origin. A charge of 6.00 ?C is located 4.68 cm along the y axis, that is, at the point (0.00,4.68) cm. Find the electric field 6.94 cm along the x axis, that is, at the point (6.94,0.00) cm. Enter the x and y components:

2)As shown in the figure, a ball of mass 0.960 g and carrying a positive charge, q = 31.8 ?C, is suspended on a string of negligible mass in a uniform electric field. We observe that the ball hangs at an angle of ? = 15.0° from the vertical. What is the magnitude of the electric field?

3)Just as you touch a metal doorknob, a spark of electricity jumps from your hand to the knob. The electric potential of the knob is 3.00×104 V greater than that of your hand. The work done by the electric force on the electrons that move from your hand to the knob is 1.70×10-7 J. How many electrons make the jump?

Explanation / Answer

Here ,

the electric field will be towards the charge as the charge is negative ,

angle of charge with x -axis , theta = 180 - arctan(4.68/6.94)

theta = 154.1 degree

Now, distance of point from charge ,

d = sqrt(4.68^2 + 6.94^2)

d = 8.371 cm

Now, magnitude of electric field = k*Q/d^2

magnitude of electric field = 9*10^9 * 3.90 *10^-6/0.0871^2

magnitude of electric field = 5.0096 *10^6 N/C

the magnitude of electric field is 5.0096 *10^6 N/C

Now, x - component = E * cos(theta)

x - component = 5.0096 *10^6 * cos(154.1)

x - component = -4.51 *10^6 N/C

the x - component of electric field is -4.51 *10^6 N/C

y - component = 5.0096 *10^6 * sin(154.1)

y - component = 2.189 *10^6 N/C

the y - component of the electric field is 2.189 *10^6 N/C

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.