Question | Answer |
the path of one object around another in space | orbit |
an unbalanced force that causes objects to move in a circular path | centripetal force |
the motion of a body when only gravity acts on it | free fall |
the curved path of a thrown object near Earth's surface | projectile motion |
the constant velocity of a falling object when the force of gravity is balanced by air resistance | terminal velocity |
the force that opposes the motion of objects through the air | air resistance |
If a baseball and a cannonball are dropped from the same height at the same time, which ball will hit the ground first? | The balls land at the same time. |
What feature does NOT affect air resistance? | its chemical properties |
If a baseball and a cannonball are dropped from the same height at the same time, which will hit the ground first? | The balls land at the same time. |
Why do astronauts in space appear weightless? | They are in free fall. |
In what direction is a projectile accelerated? | vertically downward |
Is the reaction force of a chair you are sitting on equal to your weight. | Yes |
What is a common unbalanced force acting on objects in motion? | friction |
When a train increases its velocity, does its momentum increase or decrease? | increases |
A car with a mass of 1,400 kg moves along the ice with a constant velocity of 18.0 m/s. What is the car's momentum? | 25,200 kg m/s |
When a bowling ball collides with a bowling pin, does the momentum increase or decrease? | decreases slightly |
If a moving boxcar gently collides with a boxcar at rest and the boxcars move together, what will their combined momentum be? | equal to the original momentum of the moving boxcar |
The law of conservation of momentum states that when two objects collide, what happens to their combined momentum? | remains the same after the collision |
If an action force is a cue ball hitting a billiard ball, then the reaction force is exerted on which billiard ball? | By the billiard ball on the cue ball |
How does the velocity of a falling object change over time? | the object falls faster and farther each second than it did the second before |
What is the rate at which objects fall toward Earth? | 9.8 m/s2 |
What is the symbol for change in velocity? | Δv |
What is the symbol for time the object takes to fall? | t |
What is the symbol for acceleration due to gravity? | g |
Why would a flat piece of paper take longer to fall than a crumpled piece of paper? | air resistance |
When does a falling object stop accelerating? | at terminal velocity |
What is the only force on an object in free fall? | gravity |
Where is the path of an orbiting spacecraft? | curved path following curve of Earth |
Where is the path of spacecraft in freefall due to gravity? | straight down toward Earth |
Where is the path of the spacecraft without gravity? | straight line forward |
How many directions make up projectile motion? | two |
What is vertical motion? | motion that is perpendicular to the ground |