The answer would be B) 5 m/s^2. 45 m/s-5 m/s= 40 m/s so then 40 m/s divided by 8 s would be equal to 5 m/s^2
The correct option is D.
Micheal Friday devised a wire which hanged down into a glass vessel that has a bar magnet secured at the bottom. He then filled the glass vessel with Mercury and connected the apparatus to a battery. This sent electricity through the wire, thus creating a magnetic field around it. This field interacted with the field around the magnet and cause the wire to rotate clock wisely.
I’m pretty sure that it’s true. Hope this helps