I will start from 3 basic laws of motion (Newton's laws of motion) which I can never forget
Newton's first law of motion:
"Every body continues to be in the state of rest or uniform motion along a straight line, unless compelled by an external force to act otherwise"
Newton's second law of motion:
"The rate of change of momentum of a body is proportional to the resultant force and it is in the direction of the force applied".
Newton's third law of motion:
"For every action there is an equal and opposite reaction".
