Instantaneous Speed

10.7

Instantaneous Speed

What is it?The speed at a particular time.

Any object moving at a constant speed (where distance is in equal increments), has any instantaneous speed equal to that of the constant speed (BLM 10.7 graphs 1-2)

BLM 10.7 Graphs 1-2

Any object moving at a non-constant speed (where distance increments vary) has different instantaneous speeds depending on the instant in time. (BLM 10.7 graph 3)

From a distance-time graph, with non-

constant speed, the instantaneous speed must be calculated from the slope of the tangent at any instant in time. (BLM 10.7 graph 4)

Tangent: a straight line which touches a curve at one particular point.

From a speed-time graph, with non-constant speed, the instantaneous speed can be read directly from the axis at any instant in time. (BLM 10.7 graph 5)

Calculating the average speed of a non-

constant distance-time graphs is done through slope calculations of the line which connects the start and finish points.

Calculating the average speed of a non-constant speed-time graph is difficult and will not be covered until Physics 11.

• Practice Worksheet• Textbook Questions:

page 400-401; 1, 4, 6 ab, 7, 8 (With BLM 24)

Practice worksheet

Practice worksheet

P 400-1 #6

P 400-1 #7