Name: _________________________ Hr: ______ Date: _____
Unit 2: Newton’s 2nd Law Homework Packet # 2
Mass vs. Weight
Part 1: How Much Do You Weight?
Gravity is a universal, natural force that attracts objects to each other. Gravity is the pull toward
the center of an object; let’s say, of a planet or a moon. When you weigh yourself, you are
measuring the amount of gravitational attraction exerted on you by the Earth. The
Moon has a weaker gravitational attraction that the Earth. In fact, the Moon’s gravity is only
1/6 of Earth’s gravity. So, you would weigh less on the Moon. How much would you weigh
on the Moon and on the other planets?
1. Write your weight in pounds (or an estimate) here: _______________
2. For a different planet, multiply your weight by the number given in the “New”
Weight Chart.
Example for the Moon: A person weighing 60 pounds on the Earth would weigh 10
pounds on the moon!
EX. (60 x 1/6 = 10)
3. Follow the example and fill in the blanks in the “New” Weight Chart. Show your
work.
“New” Weight Chart
Planet
Multiply your Earth weight by:
Mercury
0.4
Venus
0.9
Earth
1
Moon
0.17
Mars
0.4
Jupiter
2.5
Saturn
1.1
Uranus
0.8
Neptune
1.2
Pluto
0.01
Sun
28
Your "new" weight
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Part 2: Weight vs. Mass Problems
1. What units do we use to measure mass? ____________________
2. What units do we use to measure weight? ___________________
3. Convert the following masses to kilograms instead of grams.
(a) 100g = _______________kg
(c) 12g = ________________kg
(b) 346g = _______________kg
(d) 2345.7g = _______________kg
4. Convert the following masses to grams instead of kilograms:
(a) 15 kg = ______________g
(b) 4.692 kg = _____________g
(c) 23 kg = ______________g
(d) 5.3 kg = _____________g
5. A book has a mass of 2kg, what is its weight in Newtons? Show your work!
Use correct units!!
6. A child has a mass of 50kg. What is his weight in Newtons? Show your
work! Use correct units!!
7. You find the weight of an object on earth to be 400N, what is its mass?
Show your work! Use correct units!!
8. What is your mass in kilograms?___________________
What is your weight in Newton’s? Show your work and correct units!
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9. By comparing the mass and weight of various objects on the moon, you
obtain the following graph.
Mass v s. W ei gh t on t h e Moon
Weight (N)
Weight (N)
1 80
160
140
120
1 00
80
60
40
20
0
0
20
40
60
80
1 00
Mass (kg)
(a) Find the slope of the line. Show your work! Use correct units!!
(b) According to the graph, what is the weight of an object on the moon whose
mass is 80 kg?
(c) According to the graph, what is the mass of an object whose weight on the
moon is 60 N?
(d) Using your answer to question 8, what is your weight on the moon? Show your
work! Use correct units!!
(e) How much less would you weigh on the moon than on Earth? Show your work!
Use correct units!!
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Part 3: Eureka Video Questions
Mass
1. What’s the difference between the two rocks?
2.
What happens with the Styrofoam vs. lead experiment?
3.
To say that one thing is very lazy and the other is a little lazy means what?
4.
A question of inertia is really a question of what?
5.
How do mass and inertia relate?
6.
Does mass depend on volume?
7.
What is measurement is located in France and why is it important?
8. Why is it harder to push the lead cube rather than the Styrofoam?
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Weight vs. Mass
1. The story so far…
All masses attract all other __________ to a certain extent. The earth being
a very large mass exerts a very large force of attraction which is called the
force of gravity.
2. How many Newton’s are pulling on the apple, golf balls, and flashlight?
3. What can we use to measure Newton’s?
4. What is weight?
5. What is gravitas?
6. In physics, we measure mass using a balance in what units?
7. How is weight measured?
8. 100 g = _____________ = 1 Newton, so 60 kg = _____________________
9. Why do you weigh less on the moon?
10. Does mass change on the moon? Why?
11. Wherever you go in the universe, what stays the same, and what changes?
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Part 4: Weight Force Calculations
F=ma
g = 9.8 or 10 m/s2
WF = mg
Directions: Calculate the weight force for the objects in Newton’s. Show all work on a
separate piece of paper. Remember – weight is a force!
1.
2.
10 kg
10 g
WF = ___________
16 (lbs)
4.
3.
10 (lbs)
WF = _____________
WF_____________
165 (lbs)
1700 (lbs)
5.
WF = ___________
6.
WF = _____________
48 (tons)
7.
WF = ___________
WF = _____________
10 (ounces)
8.
WF = _____________
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