A bike is hanging from a hook in a garage. You need to consider the following forces.
(a) The force of the Earth pulling down on the bike.
(b) The force of the bike pulling up on the Earth.
(c) The force of the hook pulling up on the bike.
(d) The force of the hook pulling down on the ceiling.
Which two forces are equal and opposite because of Newton's third law?
Which two forces are equal and opposite because of Newton's first law?
I would like to say A and C for the first question and B and D for the second one but I;m not sure
a = -b because of Newton's third law.
-c -d = 0 , and therefore -c = d,
because the hook does not move. You could say that is a result of Newton's first law
the newtons first law one was wrong so I'm not sure what it would rather be
To determine which forces are equal and opposite based on Newton's laws, let's break down each force and analyze them:
(a) The force of the Earth pulling down on the bike: This force, also known as the gravitational force, is the weight of the bike pulling it downwards.
(b) The force of the bike pulling up on the Earth: This force is the reaction force to the gravitational force. According to Newton's third law, for every action, there is an equal and opposite reaction. So the force of the bike pulling up on the Earth is equal and opposite to the force of the Earth pulling down on the bike.
(c) The force of the hook pulling up on the bike: This force is the tension force in the rope or hook that suspends the bike. It counteracts the weight of the bike.
(d) The force of the hook pulling down on the ceiling: This force is the reaction force to the tension force in the rope. It is equal in magnitude but opposite in direction.
Now, let's determine which forces are equal and opposite based on Newton's third law:
According to Newton's third law, the force of the Earth pulling down on the bike (a) is equal and opposite to the force of the bike pulling up on the Earth (b). So, you are correct in saying that forces A and B are equal and opposite because of Newton's third law.
However, Newton's first law, also known as the law of inertia, states that an object at rest will remain at rest unless acted upon by an external force. In this situation, if we consider the bike hanging from the hook as the object at rest, then the forces acting on it (gravity and tension force) are not equal and opposite. So, none of the forces in this scenario satisfy Newton's first law.
To summarize:
- Forces A and B are equal and opposite due to Newton's third law.
- None of the forces satisfy Newton's first law.