Claim 2: Molecules speed up when they get energy from other molecules and slow down when they give energy to other molecules.
Energy can’t be destroyed (stated in claim 1) so claim 2 is more than likely to be correct
Answer:
Explanation:
Given
Each student exert a force of 
Let mass of car be m
there are 18 students who lifts the car
Total force by 18 students 
therefore weight of car 
mass of car 

(b)
Answer:
Blood is a homogenous mixture