Motion graphs, force graphs and acceleration
≈ 48 minMotion graphs, force graphs and acceleration
Graphs represent motion only when their axes, units and time interval are read carefully. The gradient of a velocity-time graph gives acceleration; the area under a velocity-time graph gives displacement. A force-time graph's area gives impulse, while its height is force; do not carry a graph rule from one graph type to another. A free-body diagram and a motion graph answer different questions: the diagram explains forces at an instant, while the graph describes changes over time. Linking them requires Newton's second law and a stated system.
Work it through
A velocity rises uniformly from 5 m s⁻¹ to 17 m s⁻¹ in 4.0 s. Acceleration is the velocity-time gradient: a = (17 − 5)/4.0 = 3.0 m s⁻². If the mass is constant, a positive net force must act in the chosen positive direction during that interval. The graph alone does not name which force caused it.
Mastery target
Read a velocity-time graph, calculate acceleration from gradient and connect the result cautiously to net force on a specified system.
On a velocity-time graph, what does the gradient represent?
Name the key physics term from Motion graphs, force graphs and acceleration that best fits the explanation and visual model.
Velocity changes from 5 m s⁻¹ to 17 m s⁻¹ in 4.0 s. What is the acceleration in m s⁻²?
Which statement corrects a common misunderstanding in Motion graphs, force graphs and acceleration?