Physics Help Please!

Question

1. If the distance between two electric charges doubles, then the force they exert on each other changes by how much?

(a) 4 times as big

(b) 2 times as big

Answer 1

F = kq₁q₂ / r₁₂²

 

If you double the distance, replace r₁₂ with 2r₁₂

 

F' = kq₁q₂ / (2r₁₂)² = (1/4) kq₁q₂ / r₁₂² = (1/4) F

 

Therefore, the force is reduced to one quarter.

Answer 2

(1) (d)

(2) (d)

(3) (c)

(4) (a) increases; (b) decreases

(5) (b)