Definitions
What is motion?
Movement
Who discovered gravity?
Sir Isaac Newton
How many laws of motion are there?
3
True
T/F: When a baseball player hits a ball, the ball is it equilibrium.
False - there is an unbalanced force acting on it.
What is an unbalanced force?
Force from one direction is larger than the opposite. This will cause acceleration.
True or false: a small object exerts no pull of gravity on another object.
false - everything has a gravitational pull
True/False: Every force has an equal and opposite reaction force
True
Explain how a tug-of-war represents balanced/unbalanced forces.
If the rope isn't moving, the forces are balanced. If it goes one way, there is an unbalanced force.
T/F: You would weigh the same on every planet
False
What is gravity?
The force that pulls us down to heavy objects.
T/F: If you drop two objects at the same time, the heavier one will always land first. Explain why?
False - the force of gravity is the same on Earth, no matter the mass of the object.
What is the first law of motion? Give an example of the first law of motion.
Objects in motion will stay in motion.
Objects at rest will stay at rest.
T/F: equilibrium is achieved when one force is greater than another.
False
In our experiment, why did Mr. Elliott barely move when Evan pushed off of him? Why did Evan move on the skateboard?
Because Mr. Elliott's mass is much greater. Newton's 3rd law (Equal and opposite reaction)
What is weight?
A measurement of the force of gravity pulling on an object.
Where would you weigh the most? The sun, Jupiter, Earth or Mercury? Explain.
The Sun. The heavier the object is, the more gravitational pull it has.
How do you make an object move? Which law is this an example of?
By overcoming its force in the opposite direction (unbalanced force). 2nd Law
Acceleration: something speeding up
By providing an unbalanced force.
Explain how lifting a pencil up works in terms of forces, laws of motion, unbalanced/balanced forces etc.
The pencil is in equilibrium on the desk. You provide an unbalanced force to pick it up which represents Newton's second law.
What is equilibrium?
When the forces on an object are equal making it at rest.
What year did Newton discover gravity? What was the story?
1666. He observed an apple falling from a tree and wondered what made it fall instead of floating away.
Every force has an equal and opposite reaction force.
Give three examples of balanced forces
Examples
Explain how planets are able to stay in orbit around stars? What would happen if a large unbalanced force affected the planet?
The planet is caught in the gravitational pull of the star. The planet stays in motion (1st law) so will never get fully pulled in to the star.
If big enough, the planet could be launched out of the orbit of the star.