Ch 4 Linear Motion Flashcards
How can you tell if an object is moving?
An object is moving if its position relative to a fixed point is changing
Definition of speed?
How fast an object is moving
How can you calculate speed?
Speed= distance➗time
The speed at any instant is called the _______________
Instantaneous speed
Formula for average speed?
Average speed= total distance➗time interval
How to find total distance traveled?
Total distance= average speed ✖️ travel time
What is velocity?
Speed in given direction
How is velocity different from speed?
Speed- description of how fast an object moves
Velocity- how fast and in what directions it moves
Acceleration is?
Rate at which velocity is changing
How to calculate acceleration?
Acceleration= change of velocity➗time interval
Definition of a free fall?
An object moving under the influence of the gravitational force only
What is the elapsed time?
Time that has passed since beginning of any motion
Acceleration of a free fall?
During each second of fall the instantaneous speed of the object increases by an additional 10 m/s
How to find instantaneous speed?
Instantaneous speed=acceleration✖️elapsed time
V=gt
Explain an objects instantaneous speed when it is thrown straight up in the air
Starts @ certain speed and declines by 10 m/s until it reaches its highest point (0 m/s). Then it regains speed 10 m/s at a time until it lands
For a falling object how does the distance per second change?
For each second of freefall an object falls a greater distance than it did in the previous second
Describe Speed (vertical axis) vs. time (horizontal axis) graph
The line is straight (linearity). For every increase of one second there’s the same 10 m/s increase in speed. Time and speed are direct proportions (double t, double v). It represents acceleration.
Describe distance (vertical axis) vs. time (horizontal axis)
Result is curved line. Relationship between distance and time is nonlinear. It is quadratic and the curve is parabolic. Double t, quadruple d. Distance depends on time squared. Speed increases as time passes.
How does air resistance affect falling objects
Air resistance noticeably slows the motion of things with large surface areas like falling feathers or pieces of paper. But air resistance less noticeably affects the motion of more compact objects like stones and baseballs
What is the relationship between the velocity and Acceleration
Acceleration is the rate at which velocity itself changes
When you describe the motion of one object with respect to another, we say that the object is moving _____ to the other object
Relative
