DQ2C_solution - Discussion Question 2C P212, Week 2 Forces...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Discussion Question 2C P212, Week 2 Forces Between Point Charges 1 Q Q h d q, m Consider two charges Q placed at fixed positions a horizontal distance d apart, as shown in the figure. A third particle of mass m and unknown charge q is then placed a vertical distance h above the fixed charges. The position of this third particle is arranged so that it is suspended in mid-air above the other two! This equilibrium condition occurs because the electrical and gravitational forces on the charge precisely cancel each other. (a) Calculate the charge q that is required to balance the third particle in mid-air. Express your answer in terms of the given parameters plus physical constants. 22 3/2 20 (/ 2 ) 2 ) 2 ) 2 kQq h mg dh mg qd h KQh ×− = + + ⎡⎤ =+ ⎣⎦ (b) Does your answer make sense ? Find three limiting cases where you know what the answer should be and make sure your expression for q gives the right result. . Hint: The best algebraic check is probably 0 d . Does the sign of q make sense?
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

DQ2C_solution - Discussion Question 2C P212, Week 2 Forces...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online