D.
The reading between 7N and 8N would have to be 7.5N. Answers A and B are much to small and answer C is way to big.
Answer: static electricity
Explanation:
When the plastic ruler is rubbed, friction opposes the motion and causes the transfer of electron from one surface to another such that plastic becomes negatively charged. When ruler is brought nearer to the paper, it induces the positive charge in the piece of paper.
Answer:
Insulation helps to prevent that transfer of heat.
No it shouldn't, a hypothesis doesn't need to be correct but must have an idea for why x variable effects y variable and have good reasoning. In the conclusion you should state if it's correct or not and explain why it's correct/incorrect and what answer you've determined from data.
