Select the correct answer.

A charge [tex]q[/tex] of [tex]$1.3 \times 10^{-16}$[/tex] coulombs moves from point [tex]A[/tex] to a lower potential at point [tex]B[/tex] in an electric field of [tex]$3.2 \times 10^2$[/tex] newtons/coulomb. If the distance traveled parallel to the field is [tex][tex]$1.1 \times 10^{-2}$[/tex][/tex] meters, what is the difference in the potential energy?

A. [tex]$1.22 \times 10^{-15}$[/tex] joules
B. [tex]$-2.4 \times 10^{-15}$[/tex] joules
C. [tex][tex]$32 \times 10^{-15}$[/tex][/tex] joules
D. [tex]$-46 \times 10^{15}$[/tex] joules
E. [tex]$56 \times 10^{-15}$[/tex] joules



Answer :

To find the difference in potential energy when a charge moves in an electric field, we use the formula for the potential energy difference:

[tex]\[ \Delta U = q \cdot E \cdot d \][/tex]

Here,
- [tex]\( q \)[/tex] is the charge, given as [tex]\( 1.3 \times 10^{-16} \)[/tex] coulombs.
- [tex]\( E \)[/tex] is the electric field strength, given as [tex]\( 3.2 \times 10^{2} \)[/tex] newtons per coulomb.
- [tex]\( d \)[/tex] is the distance moved parallel to the electric field, given as [tex]\( 1.1 \times 10^{-2} \)[/tex] meters.

By substituting the values into the formula, we get:

[tex]\[ \Delta U = (1.3 \times 10^{-16} \, \text{C}) \cdot (3.2 \times 10^{2} \, \text{N/C}) \cdot (1.1 \times 10^{-2} \, \text{m}) \][/tex]

When we multiply these values together, the numerical result is:

[tex]\[ \Delta U = 4.575999999999999 \times 10^{-16} \, \text{joules} \][/tex]

Now let's cross-check the available options:

A. [tex]\( 1.22 \times 10^{-15} \)[/tex] joules
B. [tex]\( -2.4 \times 10^{-15} \)[/tex] joules
C. [tex]\( 32 \times 10^{-15} \)[/tex] joules
D. [tex]\( -46 \times 10^{15} \)[/tex] joules
E. [tex]\( 56 \times 10^{-15} \)[/tex] joules

None of these options match our calculated potential energy difference of [tex]\(4.575999999999999 \times 10^{-16}\)[/tex] joules.