Gravitation JeopardyUniversal

Law of Gravitation

History Conceptual Circular Motion

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Part 1: Universal Law of Gravitation

10 Points – ULG

State Newton’s Law of Universal Gravitation.

Answer Main

10 Points Answer – ULG

• Any two objects that have mass will be gravitationally attracted to each other

MainQuestion

20 Points - ULG

State the mathematical equation for Newton’s Universal Law of Gravitation.

MainAnswer

20 Points Answer – ULG

Fgrav = Gm1m2/r2

Gravitational force = Gravitational constant*mass1*mass2/radius2

MainQuestion

30 Points - ULG

MainAnswer

• Determine the gravitational force exerted by cookie monster on a nearby cookie.– Mass of cookie monster: 200 kg– Mass of cookie: 0.3 kg– Distance between them: 5 m– G: 6.67 x 10-11

30 Points Answer – ULG

F = Gm1m2/r2

= (6.67x10-11)(200kg)(0.3kg)/(5m2) = 1.6 x 10-10 N

MainQuestion

40 Points – ULG

MainAnswer

• Sketch a graph of the gravitational force versus the distance between two objects (radius)

• And how are they related?– Proportional or Inversely Related

40 Points Answer – ULG

MainQuestion

• How are these two physical quantities related?- Inversely

proportional to the square of the distance

50 Points – ULG

MainAnswer

• How large does a planet have to be to attract you if you (70kg) were floating out in space approximately 250 m away? Assume it has to exert at least 10 N of gravitational force on you to pull you in.

50 Points Answer – ULG

• 1.33 x 1014 kg

MainQuestion

60 Points – ULG

MainAnswer

• Two planets are floating around in space, both 2 x 1023 kg. How far apart do they have to be to exert 100 N of force on each other?

60 Points Answer – ULG

1.63 x 1017 m apart

MainQuestion

Part 2: History

Main

10 Points – History

MainAnswer

• What does heliocentric mean?

10 Points Answer – History

Heliocentric:

“Sun – centered” with reference to a heliocentric solar system where the planets orbit the sun.

MainQuestion

20 Points – History

• Who was the credited with the idea of a geocentric solar system?

MainAnswer

20 Points Answer – History

• Ptolemy

MainQuestion

30 Points – History

• How were Copernicus and Galileo’s support of a heliocentric solar system different?

MainAnswer

30 Points Answer – History

• Copernicus came up with the idea of a heliocentric solar system but did not support it.

• Galileo was imprisoned for his support of the heliocentric model

MainQuestion

40 Points – HistoryDOUBLE JEOPARDY!!!

• Name three major facts about Tycho Brahe.

MainAnswer

40 Points Answer – History

• He had a midget• He had an elk that got drunk at parties• He had a gold nose• He was the king’s astronomer

• HE TOOK THE MOST ACCURATE MEASUREMENTS OF the solar system at that time

MainQuestion

50 Points – History

According to Newton, why would planets travel faster the closer they are to the sun?

MainAnswer

50 Points Answer – History

MainQuestion

• Newton explained Kepler’s laws by stating that the gravitational pull was responsible.

• If the planet is closer, it will have a stronger gravitational attraction and travel faster.

60 Points – History

• Which scientist sounds like something you would order at a restaurant?

• What was his greatest contribution?

MainAnswer

60 Points Answer – History

MainQuestion

• Cavendish

• Developed an experiment that validated the universal law of gravitation between objects on a human scale.

Part 3: Conceptual

Main

10 Points – Conceptual

Is the force of gravitation attractive or repulsive?

MainAnswer

10 Points Answer – Conceptual

• Attractive

MainQuestion

20 Points – Conceptual

Using Newton’s Universal Law of Gravitation, if the mass of one of the objects increases by 5, what happens to the force exerted between them?

MainAnswer

20 Points Answer – Conceptual

MainQuestion

• The force increases by 5.

30 Points – Conceptual

MainAnswer

• Using Newton’s Universal Law of Gravitation, if the radius between the objects increases by 5, what happens to the force exerted between them?

30 Points Answer – Conceptual

• The force decreases by 52

Or the force is 1/25 of the original force.

MainQuestion

40 Points – Conceptual

MainAnswer

• How does the gravitational force exerted by one planet in space on a second relate to the force exerted by the second planet on the first?

40 Points Answer – Conceptual

• The forces are equal (Newton’s Third Law) and opposite in direction.

MainQuestion

50 Points – Conceptual

• Using Newton’s Universal Law of Gravitation, if the radius between the objects decreases by 5, what happens to the force exerted between them?

Answer Main

50 Points Answer – Conceptual

• The force increases by 52

Or the force is 25 times the original force.

Question Main

60 Points – Conceptual

• Explain why planets orbit.• Sketch the force and velocity arrows at each

point in this diagram.

Answer Main

60 Points Answer – Conceptual

Question Main

• Planets orbit because the sun provides a centripetal force causing the planet to accelerate around it

• Velocity arrows are red – always tangent to the ellipse• Force arrows are green – always pointed toward the sun

Part 1: Circular Motion

10 Points – CM

What direction is the acceleration for an object spinning in a circle?

Answer Main

10 Points Answer – CM

• Towards the center of the circle

MainQuestion

20 Points - CM

Anna Litical is practicing a centripetal force demonstration at home. She fills a bucket with water, ties it to a strong rope, and spins it in a circle. Why does the water not fall out?

MainAnswer

20 Points Answer – CM

• Inertia keeps the water moving in a straight line, so the water “pushes against the back of the bucket” keeping it from falling out.

MainQuestion

30 Points - CM

MainAnswer

A 900-kg car moving at 10 m/s takes a turn around a circle with a radius of 25.0 m. Determine the acceleration and the net force acting upon the car.

30 Points Answer – CM

TOK:- m = 900kg- v = 10 m/s- r = 25.0 m

a = v2/r = 102/25 = 4 m/s2 F = ma = 900*4 = 3600 N

MainQuestion

40 Points – CM

MainAnswer

A tube is been placed upon the table and shaped into a three-quarters circle. A golf ball is pushed into the tube at one end at high speed. The ball rolls through the tube and exits at the opposite end. Describe the path of the golf ball as it exits the tube.

40 Points Answer – ULG

MainQuestion

Will leave the tube in the direction it was moving already (inertia)

50 Points – CM

MainAnswer

• You want to make a bowling ball travel in a circular counter-clockwise path around you (this means YOU are the center point). After you set the ball in motion “to the left”, in what direction will force need to be exerted to keep the ball in a circular path?

– You need to constantly push the ball away from you– You need to constantly push the ball toward you.– You need to constantly push the ball to the left

50 Points Answer – CM

• You want to make a bowling ball travel in a circular counter-clockwise path around you (this means YOU are the center point). After you set the ball in motion “to the left”, in what direction will force need to be exerted to keep the ball in a circular path?

– You need to constantly push the ball away from you– You need to constantly push the ball toward you.– You need to constantly push the ball to the left

MainQuestion

60 Points – CM

MainAnswer

Determine the centripetal force exerted upon a 40-kg child who makes 10 revolutions around the Cliffhanger in 29.3 seconds. The radius of the barrel is 2.90 meters.

60 Points Answer – CM

T = sec/rev = 29.3s/10rev = 2.93s

v = 2πr/T = 2π(2.90m)/2.93s = 6.2m/s

F = mv2/r = (40kg)(6.22 m/s)/(2.90m) = 533.4 N

MainQuestion

Physics CP Jeopardy

Gravitation and Circular Motion Review

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