To determine which interaction will have the strongest force between the two objects, we can use Coulomb's Law, which states that the magnitude of the electric force (F) between two charged objects is given by the formula:
\[ F = k \frac{|q_1 \cdot q_2|}{r^2} \]
where:
- \( k \) is Coulomb's constant,
- \( q_1 \) and \( q_2 \) are the amounts of the charges,
- \( r \) is the distance between the charges.
Let's analyze each interaction:
-
Interaction A:
- Charges: +2 and -2
- Distance: 1
- Force: \( F_A = k \frac{|2 \cdot (-2)|}{1^2} = k \frac{4}{1} = 4k \)
-
Interaction B:
- Charges: +1 and -1
- Distance: 1
- Force: \( F_B = k \frac{|1 \cdot (-1)|}{1^2} = k \frac{1}{1} = 1k \)
-
Interaction C:
- Charges: +2 and -2
- Distance: 4
- Force: \( F_C = k \frac{|2 \cdot (-2)|}{4^2} = k \frac{4}{16} = \frac{1}{4}k \)
-
Interaction D:
- Charges: +1 and -1
- Distance: 4
- Force: \( F_D = k \frac{|1 \cdot (-1)|}{4^2} = k \frac{1}{16} = \frac{1}{16}k \)
Now, let's summarize the forces:
- \( F_A = 4k \)
- \( F_B = 1k \)
- \( F_C = \frac{1}{4}k \)
- \( F_D = \frac{1}{16}k \)
The strongest force is in Interaction A, which has a force of \( 4k \).
Therefore, the answer is:
Interaction A