b) Explain the purpose of boron rods but explain why they need to be removed some times [2] absorb excess neutrons (NOT ELECTRONS) to stop reaction going out of control (1)
For X, this diagram shows that you would get a resultant of 0m/s:
BBC bitesize says:
"For example, two cars may be travelling at 15 m/s. If they are side by side and travelling in the same direction, their relative speed is zero. Someone looking across from one car to the other will see the other car keeping pace with them. However, if the two cars are travelling in opposite directions, their relative speed will be 30 m/s (15 + 15)."
b) Explain the purpose of boron rods but explain why they need to be removed some times [2] absorb excess neutrons (NOT ELECTRONS) to stop reaction going out of control (1)
"For example, two cars may be travelling at 15 m/s. If they are side by side and travelling in the same direction, their relative speed is zero. Someone looking across from one car to the other will see the other car keeping pace with them. However, if the two cars are travelling in opposite directions, their relative speed will be 30 m/s (15 + 15)."
"For example, two cars may be travelling at 15 m/s. If they are side by side and travelling in the same direction, their relative speed is zero. Someone looking across from one car to the other will see the other car keeping pace with them. However, if the two cars are travelling in opposite directions, their relative speed will be 30 m/s (15 + 15)."