Gravity
The force that objects exert on each other because of their masses.
Why is gravity a universal force?
Gravity acts between any two masses anywhere in the universe.
What two factors does gravitational force between two objects depend on?
Mass and distance
How is gravitational force affected by mass
As mass increases the force of gravity increases
How is gravitational force affected by distance?
As distance increases the force of gravity decreases. If distance doubles, force of gravity is one quarter, 1/4, as before.
Is the force that the Earth's gravity exerts on two masses equal?
yes
Acceleration due to earth's gravity
g=9.8m/s2
Equation to calculate force of gravity near Earth's surface
F=mg Force=massxg
How does a vacuum affect acceleration?
In a vacuum, where there is no air, all falling objects have the same acceleration
Does horizontal velocity affect acceleration due to gravity?
No, a coin thrown forward will fall to the earth at the same rate as a coin dropped.
Weight
The force of gravity on an object
How are mass and weight different on Earth and the moom
Mass is the same on both the moon and Earth. Weight is less because there is less gravity on the moon
Orbit
the elliptical path one body follows around another body due to the force of gravity. This is a centripital force.
For every 8000 meters travelled how much does Earth's surface curve downward?
5 meters. A ball thrown at 8000m/s will not hit the Earth
How does the speed of a spacecraft's launch affect its orbit?
A faster launch speed results in a higher orbit.
Escape Velocity
The launch speed needed to escape an object's gravity. A spacecraft that escapes Earth's gravity will go into orbit around the sun.
What is the Escape Velocity needed to escape the Earth's gravitational pull?
11,000m/s
What would be your weight if you were free falling while standing on a scale?
Zero
What is a microgravity environment?
Objects behave as if there were no gravity, like in a spaceship in orbit.
What effect would increasing the mass of two objects have on the gravitational pull between them?
It would increase it.
HOw does the size of the force the Earth exerts on a car compare to the force the car exerts on the earth?
The car exerts much less force on the Earth.
What would happen to the mass and weight of an object taken to a planet with twice the gravity of Earth?
The mass would be the same but the weight would increase.