Gravitation Jeopardy Universal Law of Gravitation HistoryConceptualCircular Motion

Part 1: Universal Law of Gravitation

10 Points – ULG State Newton’s Law of Universal Gravitation. AnswerMain

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 F grav = Gm 1 m 2 /r 2 Gravitational force = Gravitational constant*mass1*mass2/radius 2 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

30 Points Answer – ULG F = Gm 1 m 2 /r 2 = (6.67x )(200kg)(0.3kg)/(5m 2 ) = 1.6 x 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 kg MainQuestion

60 Points – ULG MainAnswer Two planets are floating around in space, both 2 x 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 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 – History DOUBLE 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 5 2 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? AnswerMain

50 Points Answer – Conceptual The force increases by 5 2 Or the force is 25 times the original force. QuestionMain

60 Points – Conceptual Explain why planets orbit. Sketch the force and velocity arrows at each point in this diagram. AnswerMain

60 Points Answer – Conceptual QuestionMain 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? AnswerMain

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 = v 2 /r = 10 2 /25 = 4 m/s 2 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 = mv 2 /r = (40kg)(6.2 2 m/s)/(2.90m) = N MainQuestion

Physics CP Jeopardy Gravitation and Circular Motion Review Main