Which of Newton's laws is being explained?
When you give your friend a lift on your bike you have to pedal harder and faster to keep the same acceleration as you had when you were alone.
1 answer
This scenario is explaining Newton's third law, which states that for every action, there is an equal and opposite reaction. In this case, when you give your friend a lift on your bike, the added weight of your friend is an external force acting on the system. As a result, you have to pedal harder and faster to maintain the same acceleration as when you were alone.