Question

A charge q moves from point A to point B in an electric field. The potential energy of the charge at point A is 9.4 × 10-13 joules, and its kinetic energy is zero. The kinetic energy at point B is 6.5 × 10-13 joules. What is the potential energy at B?

Answer 1

Answer:

A.  

5.6 × 10-12 joules

B.  

1.3 × 10-12 joules

C.  

2.3 × 10-12 joules

D.  

3.3 × 10-10 joules

E.  

5.6 × 10-10 joules

Explanation:

which letter answer??

Answer 2

By energy conservation we will say

$PE_i + KE_i = PE_f + KE_f$

as we know that

$PE_i = 9.4 \times 10^{-13} J$

$KE_i = 0 J$

also we have

$KE_f = 6.5 \times 10^{-13}J$

now we will have

$9.4 \times 10^{-13} + 0 = 6.5 \times 10^{-13} + PE$

$(9.4 - 6.5)\times 10^{-13} J = PE$

$PE = 2.9 \times 10^{-13} J$