unit 2
What defines force ?
A force that opposes motion
What kind of wave is a sound wave?
a mechanical wave
which is a physical property?
melting point
On average, how often does a total solar eclipse occur?
every 18 months
What is moonlight?
sunlight that reflects off the Moon’s surface
What defines field force ?
A force that act through a distance.
What kind of force is magnetic force?
a field force
Which of a physical property of matter?
volume
What is the name for the regular rise and fall of the oceans' waters?
tides
The gravitational force between the Moon and the Earth has what effect on Earth?
ocean tides
Which statement about forces is correct?
A force can be a push or a pull.
How does radar work?
Radars send electromagnetic waves. Each wave is scattered by the objects it hits. Some of the scattered waves reach back to the radar.
What are the main gases that form gas giants?
helium ,hydrogen
What is the main force that holds the stars together to form galaxies?
gravity
During the last quarter moon, how much of the Earth-facing side of the Moon is lit by the Sun?
one half of the Moon
what type of force is friction ?
contact force.
Which two variables affect the mechanical energy of an object?
potential energy and kinetic energy
Which type of rock has multiple layers and may contain fossils?
sedimentary
What is the main force that holds the stars together to form galaxies?
gravity
In which direction does Earth’s axis run through the center of the planet?
North to South
What is an unbalanced force?
a force that is not canceled out by other forces
Which defines potential energy?
a form of energy related to an object’s mass, position, or arrangement
What is a physical property?
a characteristic of a substance that can be measured or observed without changing the chemical identity of the substance
Which of these are galaxies, stars, and planets all a part of?
the universe
What is the cause of the Earth’s seasons?
the tilt of the Earth’s axis