He argued that the mass of an object does not affect the time the object takes to fall to the ground.
Objects fall to the ground at the same rate
because the acceleration due to gravity is the same for all objects.
If an object hits the ground with a velocity of 98 m/s, how long did it take to reach the ground
If an object hits the ground with a velocity of 49 m/s, how long did it take to reach the ground
This occurs only if gravity is pulling down an object with no other forces acting on it. It is usually accompanied by the playing of a Tom Petty song. :)
two places there is no air
space and a vacuum. A third place is also potentially inside an 8th graders brain. :)
the constant velocity of a falling object when the force of air resistance is equal in magnitude and opposite in direction to the force of gravity
why is terminal velocity a good thing
because if there was no maximum speed, things like hailstones would destroy everything in their path.
Why does the moon stay in orbit
because the Earth's gravitational force provides a centripetal force on it.
the curved path that an object follows when thrown, launched, or otherwise projected near the surface of Earth
leaping frog, water sprayed by a sprinkler, an arrow shot by an archer
These are all examples of projection motion.
If a rock at rest falls off a tall cliff and hits the valley below after 3.5 s, what is the rock's velocity when it hits the ground?
34.3 m/s downward
Newton's First Law of Motion
Objects in motion will remain in motion unless acted upon by another force.
the tendency of an object to resist being moved or, if the object is moving, to resist a change in speed or direction until an outside force acts on the object.
Newton's Second Law of Motion
The acceleration of an object depends on the mass of the object and the amount of force applied.
Why do newer cars pollute less than older cars?
They have less mass, so it requires less force to move them.
What is the acceleration of a 3 kg mass if a force of 15 N is used to move the mass? Note: 1 N = 1 kg×m/s
What is the acceleration of a 4 kg mass if a force of 16 N is used to move the mass? Note: 1 N = 1 kg×m/s
What is the acceleration of a 3 kg mass if a force of 18 N is used to move the mass? Note: 1 N = 1 kg×m/s
What is the acceleration of a 2 kg mass if a force of 18 N is used to move the mass? Note: 1 N = 1 kg×m/s
Newton's Third Law of Motion
Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.
Space shuttle action and reaction force pairs
Thrusters pushing the exhaust games downward as gases push the shuttle upward with equal force.
Action and reaction forces example
A rabbit's legs exerting a force of Earth with Earth exerting an equal force on the rabbit's legs causing the rabbit to accelerate forward.
Equal and opposite force
whenever an object exerts a force on another object, the second object exerts this...
What is the momentum of a ball with a mass of 120 kg that moves with a velocity of 16 m/s?
19,200 kg m/s
What is the momentum of a ball with a mass of 100 kg that moves with a velocity of 16 m/s?
16,000 kg m/s
What is the momentum of a ball with a mass of 200 kg that moves with a velocity of 16 m/s?
32,000 kg m/s
What is the momentum of a ball with a mass of 200 kg that moves with a velocity of 12 m/s?
24,000 kg m/s
What is the momentum of a ball with a mass of 100 kg that moves with a velocity of 12 m/s?
12,000 kg m/s
What is the momentum of a ball with a mass of 150 kg that moves with a velocity of 12 m/s?
18,000 kg m/s
law of conservation of momentum
this means that anytime objects collide, the total amount of momentum stays the same.
when does the law of conservation of momentum apply
then objects stick together or bounce off each other after they collide.
If a fast moving car has a greater velocity than a slow moving car....
a larger force is needed to stop the faster moving car.
Objects sticking together
After this happens, they move as one. the masses of the objects remain the same. The velocity changes. total momentum before and after collision stays the same.
Objects sticking together - examples
When one football player tackles another player or when a dog catches a ball.
Objects bouncing off one another - what is happening
Momentum is transferred from one object to another object.
Objects sticking together - what is happening
The mass of the combined object is equal to the mass of the two objects added together. Together, the one object has a velocity which is different from the velocity of the two individual items.
When a cue ball hits a billiard ball.......
the cue ball creates the action force, which makes the billiard ball move.
What is the reaction force when a cue ball hits a billiard ball.......
this is the equal but opposite force exerted by the billiard ball on the cue ball. It make the cue ball stop moving.