2BPreLec

# Electric potential energy answer next draw a picture

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: charge must be taken into account. Electric Potential Energy Answer Next, draw a picture of the situation: q=+1nC rB rA +qo List what quantities we know: q!=!+1.0x10–9C Electric Potential Energy Example A proton is placed 3.0cm to the right of a +1.0nC charged sphere. It is then brought in to a distance of 1.0cm from the sphere. What is the change in potential energy of the proton? Answer Deﬁne a coordinate system. Choose the sphere as r!=!0. Any outward distance would be positive. Electric Potential Energy Answer Start with: ∆Ue,A→B = ke q1 q2 ￿ 1 1 − rB rA ∆Ue = (8.99 × 109 Nm2 /C2 )(+1.6 × 10−19 C)(+1 × 10−9 C) ∆Ue = 9.60 × 10−17 J ￿ ￿ 1 1 − 0.01 m 0.03 m ￿ qo!=!+e!=!+1.602x10–19C rA!=!0.03m This is a positive value so potential energy increased. rB!=!0.01m What if we substituted in an electron for the proton?...
View Full Document

## This note was uploaded on 03/16/2014 for the course PHYS 1B taught by Professor Briankeating during the Spring '07 term at UCSD.

Ask a homework question - tutors are online