He discovered all planets have orbits in an elliptical shape.
Who is Kepler?
100
For a planet to have an elliptical orbit, two of these are needed. In a circle, only one is needed.
What is a focus? (or Foci - plural)
100
This law states an imaginary line drawn from the center of the Sun to the center of the planet will sweep out equal areas in equal intervals of time.
What is the Law of Equal Areas?
100
This is the value for the constant G - Universal Gravitation.
What is 6.673 x 10-11 N m2/kg2 ?
100
In Newton's equation for the law of universal gravitation, F = Gm1m2/r2, r refers to this.
What is the radius - the distance between the two centers of the two bodies?
200
His Law of Universal Gravitation gave Kepler's Laws of Planetary Motion a mechanism for interaction.
Who is Newton?
200
The amount of time it takes any body to orbit another central point is referred to as this.
What is a period?
200
This law states the ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun - sometimes represented as
T^2= 4π^2 R^3/(GM)
What is The Law of Harmonies?
200
This is the constant for g - the acceleration of gravity on Earth.
What is 9.8 m/s/s ?
200
According to Newton's law of universal gravitation in the case of a planet near the Sun, the attractive force would be this if the distance between the planet and the Sun were halved.
What is quadrupled?
300
This scientist was a renowned Danish astronomer who hired Kepler as an assistant and greatly influenced his work on planetary movement.
Who is Tycho Brahe?
300
A force that is inversely dependent upon the distance between the two objects' centers is referred to as this.
What is gravity?
300
This law states that the path of the planets about the sun is elliptical in shape, with the center of the sun being located at one focus.
What is The Law of Ellipses?
300
If the radius of the planet's orbit were doubled in the diagram below, it would have this effect on its period of orbit.
What is it would increase?
300
When Uranus was discovered, Newton's law of gravitation did NOT predict its orbit because it was being influenced not only by the Sun, but also by this planet.
What is Neptune?
400
In 1798, this scientist devised an apparatus to actually measure the gravitational force.
Who is Cavendish?
400
This mass is measured by applying a force to the object and measuring its acceleration. It can be hard to overcome.
What is inertial mass?
400
The closer together two foci are in an orbit, the more the orbit will take this shape.
What is a circle?
400
If the mass of the planet were doubled, it would have this effect on the period of its orbit.
What is it would not have any effect?
400
When he was trying to solve the riddle of gravitational attraction, Newton knew that gravity lessened when this increased.
What is distance?
500
According to Kepler's laws, the Earth will move more slowly during this time of the year because we are at aphelion - the furthest point away from the Sun during the orbit.
What is Summer?
500
This mass is measured by comparing the force of gravity of an unknown mass to the force of gravity of a known mass.
What is gravitational mass?
500
The Law of Equal Areas actually describes this aspect of a planet's orbit around the Sun.
What is the planet's speed?
500
If the mass of a planet near the Sun were doubled, the force of attraction would be this.
What is doubled?
500
If the distance between any two bodies is increased by a factor of 2, then force will be decreased by a factor of this.