March 1/2, Week # 8NB-126

Learning Target: I will• Explain the relationship

between weight and gravity.

• Differentiate between weight and mass.

Homework:• Finish the gravity exploration

Essential Question:• Which will remain the

same on Mars: mass or weight?

Agenda:• Gravity notes• Gravity explorationTO DO NOW:• Turn in your

homework (vocab) to inbox

• Prepare page 125 for Cornell Notes.

Experiment Data, NB-123

Material Time (s) Run 1 Run 2 Run 3 Average

Plastic Wrap .4008 .3826 .4386 .4073

Aluminum .3615 .2972 .3592 .3393

Wood .3841 .2863 .3693 .3322

Hypothesis: If the aluminum is used, there will be more rolling friction on the car.Data:

Results: According to the data, _________________ has the most/least rolling friction on the car.Conclusion: The data does/does not support my hypothesis because…

Gravity Cornell Notes, NB-125• Answer: The force of gravity on an object is called weight.• Answer: Mass and weight are not the same thing! Remember, mass is the amount of matter an object contains.

Questions:

• On Earth an object has 2 billion atoms. Will it still have the same amount of atoms on the Moon?

• Yes! The number of atoms will not change!!• On Earth an object has a mass of 500 grams.

Will is still have the same mass on the Moon?• Yes! The mass of an object does not change

just like the number of atoms will not change.

Gravity Cornell Notes, NB-125

ANSWER:• A 10-kilogram rock has a

mass of 10 kilograms no matter where it is in the universe. (The number of atoms)

• A 10-kilogram rock’s weight however, can vary greatly depending on where it is.

Gravity Cornell Notes, NB-125

13.1 Calculating weight

• The weight equation can be rearranged into three forms to calculate weight, mass, or the strength of gravity.

W

m g

Questions:

• On Earth an object has 2 billion atoms. Will it still have the same amount of atoms on the Moon?

• Yes! The number of atoms will not change!!• On Earth an object has a mass of 500 grams.

Will is still have the same mass on the Moon?• Yes! The mass of an object does not change

just like the number of atoms will not change.

• The following three questions were obtained at http://www.gcse.com/eb/gtest3.htm

Gravity Cornell Notes, NB-125

Question• The strength of gravity at

the Earth's surface is 10 newtons per kilogram. Calculate the weight of a car with a mass of 1500 kg.

Answer

• The formula is: • Weight = Mass ×

Gravity • Hence: • Weight = 1500 × 10 • = 15000 newtons

W

m g

Gravity Cornell Notes, NB-125

Question• The strength of gravity on

the Moon is 1.6 newtons per kilogram. If an astronaut's mass is 80 kg on Earth, what would it be on the Moon?

Answer• Mass is independent of

location, so the astronaut's mass on the Moon is the same as the astronaut's mass on the Earth.

• Hence: • Astronaut's mass on the

Moon = Astronaut's mass on the Earth

• = 80 kg

W

m g

Gravity Cornell Notes, NB-125

Question• The surface gravity of

Jupiter is about 26 newtons per kilogram. What would be the weight of a probe of mass 10 kg at Jupiter's surface?

Answer

• The formula is: • Weight = Mass ×

Gravity • Hence: • Weight = 10 × 26 • = 260 newtons

W

m g

Gravity Exploration!