universal gravitation practice quiz
TRANSCRIPT
UNIVERSAL GRAVITATION PRACTICE QUIZ
solutions
1.
The English physicist who first measured Gwas
a. Albert Einstein b. Isaac Newton
c. Charles Coulomb d. Henry Cavendish
2.
The Universal Gravitation Constant is described as
a. universal gravity b. the strength of gravity
c. distance behavior d. mass behavior
3.
True or False: The inverse square law states βIf one quantity is multiplied by a factor, another quantity decreases by the square of that factor.β
π¦ =1
π₯2
πΉ = πΊπ1π2
π2
INVERSE SQUARED LAW
π =1
π2ππ π ππ πππππππ ππ ππ¦ π ππππ‘ππ x, π‘βππ π ππ πππππππ ππ ππ¦ π ππππ‘ππ ππ
1
π₯2.
π =1
π2ππ π ππ πππππππ ππ ππ¦ π ππππ‘ππ x, π‘βππ π ππ πππππππ ππ ππ¦ π ππππ‘ππ ππ
1
π₯2.
π =1
π2ππ π ππ πππππππ ππ ππ¦ π ππππ‘ππ x, π‘βππ π ππ πππππππ ππ ππ¦ π ππππ‘ππ ππ
1
π₯2.
π =1
π2ππ π ππ πππππππ ππ ππ¦ π ππππ‘ππ x, π‘βπ π ππ πππππππ ππ ππ¦ π ππππ‘ππ ππ
1
π₯2.
ππ₯πππππ: ππ π ππ πππ’ππππ, π‘βππ π ππ πππππππ ππ ππ¦1
22=
1
4.
πππππππ 2π π€πππ πππ π’ππ‘ ππ1
4π
4.
Knowing that the universal gravitational force is given by the equation
πΉ = πΊπ1π2
π2if one of the mass is doubled and the distance is also double, how
does this change the force?
a. The force would double. b. The force would be halved.
c. The force would be the same. d. The force would quadruple.
πΉπππ = πΊπ1π2
π2πΉπππ€ = πΊ
2π1π2
(2π)2= πΊ
2π1π2
4π2=
1
2πΊ
π1π2
π2=
1
2πΉπππ
5.
Which of the following is the correct value for G?
a. 6.67 x 1011 m3 kg/s2 b. 6.67 x 10-11 m3/(kg s2)
c. 6.76 x 10-11 N /m2 kg d. 6.76 x 1011 m3/(kg s2)
6.
What is your weight at the center of the Earth?
a. the same as it was at the surface of the Earth.
b. twice the weight at the surface of the Earth.
c. half the weight at the surface of the Earth.
d. zero
7.
If you are standing on a scale in an elevator and it was accelerating downward,
your weight would be
a. greater than your normal weight.
b. equal to your normal weight.
c. less than your normal weight.
8.
What is used to explain the tides of the oceans?
a. Earthβs acceleration around the sun.
b. The pulls of the other planets.
c. Sun and Moon gravitational pulls on Earth.
d. Earthβs gravity.
9.
True or False. When the sun runs out of fusion fuel, Helium, gravitation will dominate, and the sun will start to collapse.
hydrogen
10.
A small light source located 1 m in front of an
opening of area 1 m2 illuminates a wall behind. If
the wall is 1 m behind the opening (2 m from the
light source), the illuminated area covers 4 m2.
How many square meters will be illuminated if the wall is
8 meters from the source?
ππππ = π‘βπ π ππ’πππ ππ π‘βπ πππ π‘ππππ = 82 = 64π2
a. 4 m2 b. 16 m2 c. 64 m2 d. 100 m2
11.
Consider a planet of uniform density that has a straight tunnel from the North Pole
through the center to the South Pole. At the surface of the planet, an object weighs
1 ton. What is the weight of the object if it is 2/3 of the distance to the center of the
planet.
a. 2/3 tons b. 3/2 tons c. 4/9 tons d. 9/4 tons
2
3π‘βπ π€ππ¦ ππππ π‘βπ ππππ‘ππ ππ
2
3ππ π‘βπ πππππππππ‘πππ
2
3ππ π‘βπ πππππππππ‘πππ ππ
2
3ππ π‘βπ π€πππβπ‘.
12.
Knowing that the universal gravitational force is given by the equation
πΉ = πΊπ1π2
π2, if both of the masses are doubled and the distance is also doubled,
how does this change the force?
a. The force is doubled. b. The force would be halved.
c. The force would stay the same. d. The force would quadrupled.
πΉπππ = πΊπ1π2
π2πΉπππ€ = πΊ
2π12π2
(2π)2= πΊ
4π1π2
4π2= πΊ
π1π2
π2= πΉπππ
13.
Calculate the force between two objects that have masses of 70 kilograms and
2,000 kilograms separated by a distance of 1 meter.
a. 9.34 x 10-6 N b. 2.86 x 10-6 N
c. 4.67 x 10-6 N d. 5.72 x 10-6 N
πΉ = πΊπ1π2
π2= 6.67 Γ 10β11
70 2000
12= 9.37 Γ 10β6π
14.
Calculate the forces between the two spheres
as shown in the diagram.
a. 1.85 N b. 1.85 x 10-4 N
c. 2.6 x 104 N d. 2.22 x 10-7 N
πΉ = πΊπ1π2
π2= 6.67 Γ 10β11
1000 1000
(0.3+0.3)2= 1.85 Γ 10β4π
15.
A satellite is orbiting Earth at a distance of 35 kilometers. The satellite has a mass of 500 kilograms. What is the force between the planet and the satellite?
a. 2500 N b. 3203 N c. 4845 N d. 6234 N
πΉ = 6.67 Γ 10β11(500)(5.9742Γ1024)
(6.378Γ106+35000)2= 4845 π
16.
The mass of the sun is 1.99 x 1030 kilograms and its distance from Earth is 150 million kilometers (150 x 109 meters). What is the gravitational force between the sun and Earth?
a. 2.45 x 1025 N b. 2.72 x 1024 N
c. 8.42 x 1022 N d. 3.52 x1022 N
πΉ = πΊπ1π2
π2= 6.67 Γ 10β11
1.99Γ1030 5.97Γ1024
(150Γ109)2= 3.52 Γ 1022π
17.
If the gravitational force between objects of equal mass is 4.60x10β8 N when the objects
are 100.0 m apart, what is the mass of each object?
a. 2626 kg b. 3242 kg
c. 1287 kg d. 2164 kg
πΉ = πΊπ1π2
π2
4.60 Γ 10β8 = 6.67 Γ 10β11π2
(100)2
4.60 Γ 10β8 = 6.67 Γ 10β15π2
π =4.60Γ10β8
6.67Γ10β15= 2626 ππ
18.
If two objects, each with a mass of 3.0x102 kg, produce a gravitational force
between them of 5.4 x10β6 N. What is the distance between them?
a. 3.12 m b. 1.05 m
c. 4.81 m d. 2.68 m
πΉ = πΊπ1π2
π2
5.4 Γ 10β6 = (6.67 Γ 10β11)(3.0Γ102)2
π2
π2 =6.67Γ10β11 (3.0Γ102)2
5.4Γ10β6π =
6.67Γ10β11 (3.0Γ102)2
5.4Γ10β6= 1.05 π
19.
What is the gravitational force on a 150.0-kg object that is 5.25x107 m above the
Earthβs surface?
a. 17.0 N b. 21.4 N c. 150 N d. 32.8 N
πΉ = πΊπ1π2
π2
πΉ = 6.67 Γ 10β11(150)(5.97Γ1024)
((6.371Γ106)+(5.25Γ107))2
πΉ = 17.02 π
20.
True or False, a 1000-kg object placed exactly between the Moon and the Earth will eventually falls towards the Moon.