Mass Vs. Distance
What is gravity?
A force that attracts mass; a force that pulls objects together.
Mass stays the same no matter where you go in the universe
True
Kepler’s 1st Law states that planets move in what shape?
Ellipse
When you feel "weightless" in a falling elevator, how does your mass change?
It stays the same.
If you double the mass of an object what will happen to its gravity?
Its gravity will double, increase.
What does weight measure?
The force of gravity on a object
The point where a planet is closest to the sun is called the ___ and the point where a planet is furthest from the sun is called the _____.
Perihelion, Aphelion
What do we call it when the only force acting on an object is gravity?
Free Fall
If two planets move farther apart, the gravitational force between them..
Decreases
You measure your mass on earth and it is 40 kg. If you went to the moon what would your mass be?
40 kg
According to Kepler’s 2nd Law, a planet moves fastest when it is...
Closest to the sun
If you are standing in an elevator accelerating upward, does your apparent weight go up, go down, or stay the same?
Apparent weight goes up
Which has a stronger pull on the Earth: The Sun or the Moon?
The sun due to its mass
The standard unit for weight is:
Newtons
Kepler’s 3rd Law relates a planet's orbital period to its..
distance from the sun
If you drop a feather and a hammer on the moon( no air) which one will hit the ground first?
Neither, both hit the ground at the same time.
The sun is more massive than the earth. Lets say the sun exerts 1 billion newtons of force on the earth. Give a number for how much force the earth exerts on the sun.
1 billion Newtons
Why would you weigh less on mars than on earth?
Because the force of gravity on mars is weaker than the earth.
True or False: Planets move at a constant speed all year long.
False
Why do astronauts feel weightless on the international space station?
Because both their body and the space station are in free fall.