A distance time graph has distance on the y axis (usually in metres) and time on the x axis (usually in seconds). The gradient of the line (change in y/ change in x) is the speed. If the line is flat then the object is stationary.
To calculate average speed use
speed (m/s) = distance travelled (m)/ time taken (s)
Apparatus: stop watch and metre rule
mark the start and end positions for the know distance
use a metre rule to measure the distance
line up front of car with start point, release and start timer
move eyes to end point
stop timer when front of car passes end point
improve by repeating and averaging
make sure car starts from stationary
calculate average speed using : average speed = distance travelled/ time taken
on a velocity time graph the velocity-time graph the velocity is on the y axis (usually in m/s) and time is on the x axis (usually in s). If the line is flat then the object is moving at a constant velocity. the gradient of the line is the acceleration. The area under the line is the distance travelled.
Gradient = acceleration= change in y/ change in x = change in velocity/time
The area under the graph can be calculated as rectangles and triangles, or by counting boxes, is equal to the distance travelled.
v2=u2+2as
v= final speed
u= initial speed
a= acceleration
s= distance moved
see all the rearrangements of this equation.
