Gravity

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Gravity
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What is gravity?

• Its a force that pulls objects towards each
  other.

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What is free fall?

• It is when the only force acting on an object is
  gravity.

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How fast is gravity?
9.8 m/s2.

• Acceleration due to gravity is
• This means that for every second an object is in
  acceleration due to gravity, its speed is
  increasing by 9.8 m/s.
• At t1s, speed
• At t2s, speed
• An objects velocity increases at for
  every second it falls.

9.8 m/s
19.6 m/s
9.8 m/s
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What happens if you throw an object horizontally?

• First of all, objects that are thrown
  horizontally are called projectiles.
• If a projectile is thrown, it will hit the ground
  at the same time an object in free fall will, if
  they start moving at the same time.

Do you believe this, or should we test it?
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Why didnt our objects hit the ground at the same
time?

• What does air resistance do?
• Air resistance is a fluid friction that causes
  objects to hit the ground at different times. It
  acts opposite of gravity.

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What happens when air resistance equals the force
of gravity on an object?

• Terminal velocity is when

an object in free fall reaches its greatest
speed theres no acceleration. Gravity air
resistance.
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What is weight?

• Weight is the force of gravity on an object.

It can be calculated by
Mass x acceleration due to gravity Mass x 9.8 m/s2
Weight Weight
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Calculate your mass using the above formula and
value for acceleration

• Mass weight
• 9.8 m/s2

Mass lb x 0.4536 kg mass kg 1 lb
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Another Law to follow

• The law of universal gravitation is the law that
  states that gravity acts between all objects in
  the universe.