forces and energy Flashcards
Origin or reference point
the initial position of an object
distance
the difference between two position measurements
how is distance represented?
d
time
the difference between two time measurements
how is time represented?
t
speed
the rate of change of position
about average speed:
Average speed does not take into consideration the path or direction the object traveled to reach its destination
written formula for average speed:
Average speed = distance an object travels (including curved lines)/time taken for the journey.
what are the three simple equations for finding variables concerning speed?
s=d/t, t=d/s, d=sxt
position
the place relevant to an agreed origin
what is a scalar quantity?
a quantity that just has magnitude (size). They have no direction such as speed, distance and time
what is a vector quantity?
a quantity which has magnitude and direction, including velocity and force
what is a position time graph?
show the movement of an object from it’s origin. as time progresses, the object will either move further away from the point of origin, stop and not move or return closer to the point of origin.
acceleration
the term used when the rate of speed of an object is increasing- m/s^2
deceleration
the term used when the rate of speed of an object is decreasing
slope of a line on a graph
- the “steepness” of a line is called its slope
- the rise is equal to the height of the triangle
- the run is equal to the length along the base of the triangle
slope of position-time graphs
- the slope is the gradient
gradient = rise/run, which equals speed
Position time graphs and speed
- a steeper line on a position vs. time graph means a faster speed
- a line with zero slope means the object is not moving
about a velocity (speed)-time graph?
- a straight sloped line with positive slope means the object is accelerating or speeding up at a constant rate.
- a horizontal line means the object is travelling at a constant speed
- A straight sloped line with negative slope means the object is decelerating at a constant rate.
- The slope of the line shows how fast the object is acelerating or decelerating
average speed:
a single value for speed that best represents the motion of an object; speed change divided by time interval.