Idea 8of 11Builds onHow fast the speed changesThe average sits halfwayThe area under the line
One picture, three equations
Why does the course give you three equations?
Today you'll discover
- three readings of one graph
- how each equation compresses a reading
- a bench to feel the three dials
Think firstOne graph. How many things can you read off it?
From the cart's line, which can you read: how fast it changes, its average, how far it went?
Answer first, then press Next. Each equation is one reading of the same line.
The cart's velocity–time graph. After a prediction, the slope triangle is shaded with its equation; then the dashed midline with its equation; then the rectangle under the midline with the displacement equation and 16 metres east. Then a bench with three sliders, start, end and time, with readouts and three challenges. The last step asks which reading finds how far for a cart from rest.
See the whole ideathe big idea and the key word, in one place
The big idea
One picture, read three ways: slope, midline, area.
Where it goes nexta = Δv ÷ Δt is the slope. Δd = ((v₁ + v₂) ÷ 2) Δt is the midline times the width. Δd = v₁Δt + ½aΔt² is the rectangle plus the triangle.
Key word
- equations of motion
- the equations relating displacement, velocity, acceleration and time under uniform acceleration; each is the velocity–time graph read one way
About this modelBelow the line means moving the other way, not slowing down.
Below the line means moving the other way, not slowing down.
Ready to use it?
- Match each equation to the part of the graph it reads.