Answer:
The answer to your question is the letter D. 2.5 N
Explanation:
The electrostatic force is the same in both directions,
If the electrostatic force on B due to A is 2.5 N, the magnitude of the electrostatic force on A due to B must be 2.5N.
Maybe the direction is different but the magnitude is the same.
List out all the variables that you do know;
acceleration=-9.8 ms⁻¹ (this remains constant on Earth)
Final velocity=?
Displacement (s)= -2.1 m
Initial Velocity(u)=2.5 ms⁻¹
v²=u²+2as
v²=(2.5)²+2(-9.8)(-2.1)
v²=47.41
v=√47.41
v=6.88549 ≈ 6.9 ms⁻¹
Hope I helped :)
B- light bends as it passes through an object ( a would be reflect)