chapter 2, section 1 notes gravity and motion. history

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Chapter 2, Section 1 Notes Gravity and Motion

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Page 1: Chapter 2, Section 1 Notes Gravity and Motion. History

Chapter 2, Section 1 Notes

Gravity and Motion

Page 2: Chapter 2, Section 1 Notes Gravity and Motion. History

History

Page 3: Chapter 2, Section 1 Notes Gravity and Motion. History

Aristotle was the first to discuss gravity.

Page 4: Chapter 2, Section 1 Notes Gravity and Motion. History

He believed that the amount of gravity was dependent on an

object’s mass.

Page 5: Chapter 2, Section 1 Notes Gravity and Motion. History

Galileo Galilei challenged Aristotle

Page 6: Chapter 2, Section 1 Notes Gravity and Motion. History

He argued that mass of an object does NOT affect the time it takes that object to fall to the ground.

Page 7: Chapter 2, Section 1 Notes Gravity and Motion. History

He tested this by dropping two cannon balls of different masses to the ground. They hit at the

same time!

Page 8: Chapter 2, Section 1 Notes Gravity and Motion. History
Page 9: Chapter 2, Section 1 Notes Gravity and Motion. History

Gravity and Acceleration

Page 10: Chapter 2, Section 1 Notes Gravity and Motion. History

Acceleration is the rate at which velocity changes over time.

Page 11: Chapter 2, Section 1 Notes Gravity and Motion. History

Objects fall to the ground at the same rate because the

acceleration due to gravity is the same for all objects.

Page 12: Chapter 2, Section 1 Notes Gravity and Motion. History

Acceleration of all object toward Earth= 9.8 m/s2

Page 13: Chapter 2, Section 1 Notes Gravity and Motion. History

Acceleration depends on force and mass.

Page 14: Chapter 2, Section 1 Notes Gravity and Motion. History

An object with a lot of mass does have a larger force acting upon it, but it is harder to accelerate. This is why objects of different mass

can fall with the same acceleration

Page 15: Chapter 2, Section 1 Notes Gravity and Motion. History

Velocity of Falling objects

Page 16: Chapter 2, Section 1 Notes Gravity and Motion. History

• To calculate the change of velocity of a falling object, use the following equation

• V= g x t• • = change• V= velocity• g= acceleration due to gravity, 9.8m/s2

• t= time( seconds)

Page 17: Chapter 2, Section 1 Notes Gravity and Motion. History

Air Resistance and Falling Objects

Page 18: Chapter 2, Section 1 Notes Gravity and Motion. History

Air resistance is the force that opposes the motion of objects

through air.

Page 19: Chapter 2, Section 1 Notes Gravity and Motion. History

Air resistance is dependent on size, shape and speed of an object. For

example, air resistance would affect a flat piece of paper more than a

crumpled pieces of paper.

Page 20: Chapter 2, Section 1 Notes Gravity and Motion. History
Page 21: Chapter 2, Section 1 Notes Gravity and Motion. History

Increased speed = more air resistance

Page 22: Chapter 2, Section 1 Notes Gravity and Motion. History

Air resistance will increase until it is balanced with the downward

force of gravity.

Page 23: Chapter 2, Section 1 Notes Gravity and Motion. History

Once the net force is 0 Newtons, the object will fall at a constant velocity known as its terminal

velocity

Page 24: Chapter 2, Section 1 Notes Gravity and Motion. History

If there is no air resistance, and object is said to be in free fall.

Page 25: Chapter 2, Section 1 Notes Gravity and Motion. History

Free Fall occurs if the only force acting on

an object is gravity.

Page 26: Chapter 2, Section 1 Notes Gravity and Motion. History

Free fall can only occur where there is no air, such as in a

vacuum.

Page 27: Chapter 2, Section 1 Notes Gravity and Motion. History

Orbiting Objects are in Free Fall

Page 28: Chapter 2, Section 1 Notes Gravity and Motion. History

An object orbits when it travels around another object in space.

Page 29: Chapter 2, Section 1 Notes Gravity and Motion. History

A spacecraft that orbits Earth moves forward, but is also in free fall towards Earth, this causes the

spacecraft to orbit.

Page 30: Chapter 2, Section 1 Notes Gravity and Motion. History

The 2 forces ( forward + down) allows the shuttle to follow the

curve of the Earth’s surface, and allows it to orbit.

Page 31: Chapter 2, Section 1 Notes Gravity and Motion. History
Page 32: Chapter 2, Section 1 Notes Gravity and Motion. History

The astronauts inside a spacecraft are also in free fall, which is why

they float.

Page 33: Chapter 2, Section 1 Notes Gravity and Motion. History

Other objects also orbit in space.

( the moon, planets, star, etc)

Page 34: Chapter 2, Section 1 Notes Gravity and Motion. History

Objects that orbit are in a constant circular motion, and are always

changing direction. This is caused by a constant unbalanced force, known

as centripetal force. This force is caused by gravity.

Page 35: Chapter 2, Section 1 Notes Gravity and Motion. History

Projectile Motion and Gravity

Page 36: Chapter 2, Section 1 Notes Gravity and Motion. History

Projectile motion is the curved path an object follows when it is

thrown or propelled near the surface of Earth.

Page 37: Chapter 2, Section 1 Notes Gravity and Motion. History

There are two components to projectile motion

• horizontal motion: motion that is parallel to the ground

• vertical motion: motion that is perpendicular to the ground(gravity)

Page 38: Chapter 2, Section 1 Notes Gravity and Motion. History
Page 39: Chapter 2, Section 1 Notes Gravity and Motion. History

Examples of projectile motion:

• frog leaping• diving into a pool• shooting an arrow

Page 40: Chapter 2, Section 1 Notes Gravity and Motion. History