Force Due to Gravity Problems
1. If I am unhappy with my weight here on earth, how can I change it without losing mass?
2. An economy car has a mass of 1300 kg. What is its weight in Newtons here on Earth? (12,740 N)
3. A small yacht weighs 14,700 N. What is its mass in kg here on Earth?
4. The apple Sammy ate for lunch weighs 1 N. a) What is its mass in grams?
b) What is the apple’s weight in pounds? (hint: dimensional analysis)
5. a) What is the mass and weight of a 10kg object on Earth?
b) What is the same object’s mass and weight on the moon where the force of
gravity is 1.6 m/s/s?
6. Andrew has a mass of 54 kg. What is his weight in Newtons on Earth?
7. What is his weight in pounds on Earth? (1 lb = 4.44 N)
8. How much would Andrew weigh in Newton’s on the Mars? (gmars = 3.8 m/s/s)
9. What is his weight in pounds on the Mars?
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10. If Bailey has a mass of 45 kg, what is her weight in Newtons on Earth?
11. What is Bailey’s weight in pounds on Earth?
12. On planet Billabong, Bailey weighs 650 Newtons. What is the acceleration due to gravity on
planet Billabong?
13. On Planet Zebulon, Bailey weighs 60 pounds. What is the acceleration due to gravity on
Zebulon?
More Practice (Review).
14. If something falls to the ground on Earth (assuming no air resistance), how fast is
it going after 15 seconds?
15. What is the gravity on planet BeRo if an object with a weight of 803 N has a mass of 53 kg?
16. What is the gravity on BeRo’s moon if it is 1/12th that of the gravity on the planet?
17. How does the size of a planet affect its gravity constant (G)?
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Force Due to Gravity Problems
1. If I am unhappy with my weight here on earth, how can I change it without losing mass?
Go to a different planet where the acceleration due to gravity is less.
2. An economy car has a mass of 1300 kg. What is its weight in Newtons here on Earth?
Givens:
m = 1300 kg
g = 9.8 m/s/s
w=?
W = M ● g = 1300 kg x 9.8 m/s/s = 12,740
N
3. A small yacht weighs 14,700 N. What is its mass in kg here on Earth?
W = M ● g so… M =
W
g
=
14,700 N
9.8 m/s2
=
1500 kg
4. The apple sammy ate for lunch weighs 1 N.
a. What is its mass in grams?
m=
w
g
=
1N
9.8 m/s2
= 0.1 kg
0.1 kg
1
1000 g
1 kg
= 100 g
b. What is its weight in pounds? (1 kg = 2.2 lbs.)
0.1 kg
1
2.2 lbs.
1 kg
= 0.22 lbs
5. a. What is the mass and weight of a 10kg object on Earth?
The mass is 10 kg
To find weight
plug numbers
into w = m x g:
w = m x g = 10 kg x 9.8 m/s2 =
98 N
b. What is the same object’s mass and weight on the moon where the force of gravity is 0.16 (or
1/6th) that of Earth?
The mass is 10 kg
(mass does not change. It is a measure of the amount of
matter in an object. ).
To find weight, first determine the acceleration due to gravity on the moon:
9.8 m/s/s ● 0.16 = 1.6 m/s/s
Then plug numbers into W = M●g:
w = m ● g = 10 kg * 1.6 m/s2 =
16 N
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6. Andrew has a mass of 54 kg. What is his weight in Newtons on Earth?
Givens:
m = 54 kg
g = 9.8 m/s/s
w=?
w = m ● g = 54 kg x 9.8 m/s/s = 529.2 N = Andrew’s weight
7. What is his weight in pounds on Earth? (1 lb = 4.44 N)
529.2 N
1
1 lbs.
4.44 N
= 119.2 lbs = Andrew’s weight
8. How much would Andrew weigh in Newton’s on the Mars? (gmars = 3.8 m/s/s)
Givens:
m = 54 kg
g = 3.8 m/s/s
w=?
w = m ● g = 54 kg x 3.8 m/s/s = 205.2 N = Andrew’s weight on Mars
9. What is his weight in pounds on the Mars?
205.2 N
1
1 lbs.
4.44 N
= 46.2 lbs = Andrew’s weight on Mars
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10. If Bailey has a mass of 45 kg, what is her weight in Newtons on Earth?
Givens:
m = 45 kg
g = 9.8 m/s/s
w=?
w = m ● g = 45 kg x 9.8 m/s/s = 441 N = Bailey’s weight on Earth
11. What is Bailey’s weight in pounds on Earth?
441 N
1
1 lbs.
4.44 N
= 99.3 lbs = Bailey’s weight on Earth
12. On planet Billabong, Bailey weighs 650 Newtons. What is the acceleration due to gravity on planet
Billabong?
Givens:
m = 45 kg
g = ??
w= 650 N
w = m ● g so…
g=
w
m
=
650 N
45 kg
=
14.4 m/s/s = g on Billabong
13. On Planet Zebulon, Bailey weighs 60 pounds. What is the acceleration due to gravity on Zebulon?
60 lbs
1
w = m ● g so…
4.44 N
1 lb.
g=
= 266.4 N = Bailey’s weight on Zubulon in N
w
m
=
266.4 N
45 kg
=
5.9 m/s/s = g on Zebulon
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