Newton's laws
Who is Isaac Newton
Famous physicist.
A 95 kilogram man punches a wall with a force of 20 Newtons (unit of measurement for force). What is the rate of acceleration of the punch (in m/s^2)?
4.75 m/s^2
What is gravitational potential energy?
The energy that an object with mass could have in relation to another object with mass as a result of gravity.
What concepts of physics did we apply to the egg drop?
Kinetic and Potential Energy, Air Resistance, elasticity, etc.
Name one of his discoveries
gravity, first, second, and third laws of motion.
What is buoyancy?
The ability of an object to float
How does air resistance decrease potential energy?
Air resistance pushes against the force of gravity when an object is falling, which in turn slows the object down, and reduces the total potential energy of an object.
What was the high score for the most pennies on a penny boat in both 8th grade classes?
384
What is Newton's third Law?
For every action there is an equal and opposite reaction.
If the mass of an object is really large, but the surface area is really small, is it likely to float? Why?
no, in order for an object to have buoyancy, it has to have small mass compared to the surface area of the object.
What is Kinetic energy?
It is the energy of motion in a moving object.
Looking back at it, how could you have made your penny boat better?
Increase surface area to mass ratio
Two cars are going down the road. Car A hits a wall at 75 MPH and weighs 3 tons. Car B hits the wall at 65 MPH and weighs 4.5 tons. Which of the cars hit the wall with the most force?
Car A had a force of 225 while car B had a force of 292.25. Car A had the most force.
When you jump, you push down quickly on the ground. If you are pushing down, why do you go up?
According to Newton's third law, for every action there is an equal and opposite reaction. The downward push of my feet on the ground caused an opposite (upward) push (reaction) from the ground on me.
Why does kinetic energy increase as potential energy decreases?
Total energy remains constant, and as an object decreases in potential energy (i.e. an object gets closer to the ground), the object increases in kinetic energy. The opposite is also true.
Why were a lot of the egg drops successful in not breaking the egg?
Because they had parachutes to add air resistance (which decreases total energy), and adding cotton balls to absorb the impact of the fall.
Name and explain every one of Newton's laws
1. An object in motion will stay in motion and an object at rest will stay at rest in the absence of outside forces
2. Force = Mass x Acceleration
3. For every Action there is an equal and opposite reaction.
Why does a rubber ball bounce higher than a golf ball?
The rubber ball is much more elastic than the golf ball is.
We drop a ball with a potential energy of 10 Joules (Unit of measurement for energy) and a kinetic energy of 0 Joules from the balcony outside. If we take calculations of its energy from the top point, halfway to the ground, and when it hits the ground, what is the potential and kinetic energy at each point.
drop height PE: 10 Joules, KE: 0 Joules
Half way down PE: 5 Joules, KE: 5 Joules
ground level: PE: 0 Joules, KE: 10 Joules
Name and describe any of the labs we did for Newton's second law.
Chair races (push students of different heights on a chair) or speed it up (use a piece of paper to push different balls as fast as you can).