Question

The slope on a distance-time graph shows a ball moving from 20 m to 40 m in 1 s and from 40 m to 80 m in the next second. Which describes the ball’s motion between 20 m and 80 m on the graph?

Answer 1

45 is the correct answer

Answer 2

slope of the graph on first part of the motion

$slope = \frac{\Delta x}{\Delta t}$

$slope = \frac{40 - 20}{1}$

$slope = 20$

for next part of motion similarly

$slope = \frac{\Delta x}{\Delta t}$

$slope = \frac{80 - 40}{1}$

$slope = 40$

so this shows the slope of the motion is not same during two interval of time

it shows that the velocity of the motion is not constant and increasing here with time

SO this shows and accelerated motion from initial to final and the overall slope of the motion is given by

$slope = \frac{\Delta x}{\Delta t}$

$slope = \frac{80 - 20}{2}$

$slope = 30$