Name:
Physics Challenge Question 3: Velocity and acceleration
Due in class 9/29/2008
Hint for the following:
Just like velocity tells us how position changes with time (slope of an x-t graph),
acceleration tells us how velocity changes with time.
The graphs below show the velocities (v) of two different people running, as a function
of time (t). You will need no calculations for the questions below, only the graphs. But,
be sure to show your work!
v (m/s)
v (m/s)
5
5
4
4
3
3
2
2
1
t (s)
1
2 3 4 5 6 7 8 9 10
1
t (s)
1
2 3 4 5 6 7 8 9 10
Part 1: (answer for both graphs)
During which intervals of time is the acceleration positive? Negative?
Part 2: (answer for both graphs)
Is the acceleration ever 0? If so, when?
Part 3:
Which person runs farther during the first 10 seconds?
(Hint: what are the units of v  t )