Why is friction force considered a contact force?
Friction is produced when objects slide past one another.
What is the total net force to the right and why?
100 N
When they forces are in the same direction you add
New, full, gibbous, quarter, and crescent describes what?
Moon Phases
Which term best describes the spinning of Earth that causes day and night?
What kind of force is gravity?
noncontact
Why are some forces considered to be noncontact forces?
Objects do not have to touch each other to experience a force.
When the moon is waning, its lighted part appears to _____. What side of the moon is bright?
Decrease in Size
Left
The cycle of the moon’s phases repeats in a predictable way. How long does it take to cycle from one new moon to the next new moon?
One Month
What describes the gravitational force from a planet?
large and pulls objects toward itself
Two baseballs are sitting 3 meters apart and are not moving. Explains why the gravitational force does not cause them to move?
The gravitational force between the two objects is weak because their masses are small.
Which description best defines the term season?
A) the time it takes Earth to complete one full rotation on its axis
B) the time it takes Earth to complete one revolution around the sun
C) a specific time of the year that is characterized by recurring weather conditions
D) a time of year that is characterized by constantly changing weather conditions
C
A student made a model of a lunar eclipse. Which change will he need to make to the model to change it into a model of a solar eclipse instead?
Move the moon between the sun and Earth.
When a comet enters the solar system, it moves toward the sun. Why doesn’t the sun move when a comet is nearby?
The sun and comet apply an equal force on each other, but the sun does not move because its mass is greater than the comet’s.
When two objects having different masses collide (crash), they move away from each other at different speeds. Which is true of the forces exerted at the moment of impact?
The forces exerted when they collide are equal and opposing.
When does a solar eclipse take place?
when Earth moves into the moon’s shadow,
Sun Moon Earth
When the Earth is in between the Sun and the Moon, which moon phase is happening?
Full Moon
If someone drops a glass bottle, it falls to the ground. Why doesn’t the gravitational force between the person’s hand and the cup keep the glass bottle from falling?
There is a gravitational force between the hand and the glass bottle, but Earth’s gravity is stronger, so Earth’s gravity pulls the glass bottle down.
Planets A and B are both the same size, but planet B has three times the mass of planet A. How does the weight of an object compare on the two planets?
The weight of an object is three times larger on planet B.
Describe the order of the celestial bodies (Earth, Sun, and Moon) during a lunar eclipse?
The Earth is between the Sun and the moon. Earth's shadow is casting onto the moon.
What is a factor that contributes to Earth’s seasons?
The angle of the sun
Number of daylight hours