Motion Graphs Grade 10 Science Distance-Time Graphs The shape of a distance-time graph gives information about an object’s speed. Q:What can you say about the speed depicted in each graph below? A no speed constant speed B a is higher than b acceleration Determining Speed Graphically A distance-time plot can be used to determine speed using slope. Q: Use the graph to determine the speed of a hiker during segments P-R and R-S. Determining Velocity Graphically To graph velocity, a displacement-time graph is required. If motion is in one direction only, the displacementtime graph is identical to the speed-time graph. Q:What conclusions can you draw about the motion of a car from the graph above? Displacement Determining Velocity Graphically Instantaneous Velocity When the shape of the displacement-time graph is not linear (that is, when velocity is not constant), we may find it useful to calculate an instantaneous velocity. This is done by drawing a line tangent to the curve at a given point and calculating its slope. Instantaneous Velocity Q: Calculate the instantaneous velocity of the object whose motion is graphed below at t = 1 s and t = 3 s. Self-check: do your results match the shape of the graph?
