A metal sphere hangs from a string and has 2 kg of mass. The sphere has a charge
ID: 2124973 • Letter: A
Question
A metal sphere hangs from a string and has 2 kg of mass. The sphere has a charge of +6.5 C. A uniform electric field is turned on and directed to the right.
A) What is the electric force on the metal sphere if the magnitude of the electric field is 106 N/C?
B) When the sphere reaches equilibrium, what is the angle that the string makes with the vertical axis (assuming the same electric field as part (a)?
A metal sphere hangs from a string and has 2 kg of mass. The sphere has a charge of +6.5 mu C. A uniform electric field is turned on and directed to the right. What is the electric force on the metal sphere if the magnitude of the electric field is 106 N/C? When the sphere reaches equilibrium, what is the angle that the string makes with the vertical axis (assuming the same electric field as part (a)?Explanation / Answer
A) F = q E = 6.5E-6*10^6 = 6.5 N
B) sum forces in the y:
T cos theta - m g = 0
T = mg/cos(theta)
sum forces in the x:
F - T sin theta = 0
6.5 = mg tan(theta)
theta = arctan( 6.5/(2*9.81))=18.33 degrees