The Difference between Mass Weight Thats heavy man

The Difference between Mass & Weight That’s heavy man. Heavy…

What we learned last time: Gravity is dependant upon the mass of two objects and the distance between them. – If mass increases – Force of Gravity increases – If distance increases – Force of Gravity decreases. Jupiter has more mass than Earth; Therefore it has more gravity The satellite is farther from the center of Earth than we are; Therefore the planet is not pulling as hard on the satellite as the person standing on the surface!

What is Weight? • Definition: Weight is a measurement of how strongly gravity pulls on a mass. • Weight is completely dependent on the amount of gravity there is. • It the result of the force of gravity!!! • Without gravity there is NO WEIGHT (the ultimate diet plan!!!)

What does weight depend on? • The weight of an object depends on the object’s mass. – In fact, an object’s weight is directly proportional to the object’s mass. • The weight of an object also depends on the object’s location. – In fact, an object’s weight is directly proportional to its free fall acceleration, g at its current location.

Amount of Mass & Gravity = Weight • If you add more mass – you’ve increased the attractive force between you and the The Earth earth must really • Therefore you “weigh” more! like me!

Gravity, Distance and Weight: • If I leave the earth and head to outer space, I am farther away from the gravity source. • Therefore, you weigh less. Dude! I CAN FLOAT AROUND!

Mass ≠ Weight • Mass and Weight are NOT the same thing! • Mass: Amount of matter an object contains – Has inertia (resistance to a push/pull) • Weight (Force): – Dependant upon Gravity (mass is not) • Attraction between two objects • Can change if the objects change distance or mass

Mass and Weight are different! ► Mass is an intrinsic property of an object. It is completely determined by the number and type of atoms that make up the object. It does not depend on the environment in which the object is located. ► But weight is different. Weight depends on both the object itself, and on some other object that exerts the gravitational force.

Weight really is a measurement of the gravitational attraction between you and the earth. Mass and Gravity = Weight Remember – Weight is a force measurement When gravity pulls on your mass, the resulting force is called “weight”! Source of Gravity Small mass = less pull = less weight Source of Gravity Large mass = more pull = more weight

Compare: Mass vs. Weight on different planets: Same person on Jupiter is 354. 6 lbs!!! Person on Earth is 150 lbs! Why is this true? What is different between Jupiter and Earth? Jupiter has more mass than the Earth Therefore it has more gravity! Your same mass would weigh more on Jupiter than on Earth! Q: Did the person’s MASS (amount of matter that makes them up) ever change?

Q: How does gravity accelerate an object? How objects fall as a result of gravity was a matter of debate for scientific thinkers as far back as ancient times! A “philosopher” named Aristotle felt that heavier objects (greater weight) would fall faster than lighter objects when pulled by gravity… This idea was accepted for 100’s of years! After many years (during the renaissance) a scientist named Galileo had a different idea: To try and prove his idea, he took cannon balls to the top of the leaning tower of Pisa… And then he dropped them!!! He felt that all objects would fall at the same rate no matter what the mass or weight was…

Test of Gravity • Which one fell faster – the heavier one or the lighter one? • Galileo found that no matter how large or small, the objects fell at the same Velocity. • So at what rate do objects accelerate due to Earth’s gravity?

Acceleration Rate of the Earth What is the acceleration of this interval? 1 sec – 9. 8 m @ 9. 8 m/s What is the acceleration of this interval? 2 sec – 19. 6 m @ 19. 6 m/s What is the acceleration of this interval? 3 sec – 44. 1 m @ 29. 4 m/s • Gravity’s Acceleration on the Earth = 9. 8 m/s 2

Wait a second! We already talked about how leaves and feathers fall very slowly and even changes directions So what makes the leaf and feather fall differently than a cannon ball? So will feathers and leaves always fall slower than cannon balls?

Q: So what if we got rid of all the air? Galileo Experiment – Apollo 15 Hammer & Feather Experiment Google Video

So how do we solve for weight? Force = Mass x Acceleration Rate of Earth’s Gravitational Pull Weight = Mass x Gravity Acceleration

• Compare your weight on Earth to what is would be on the Moon: • Discuss: Why does your weight change? • Discuss: Does your mass change as well?