Practice for next Wednesday's test

Here are some practice problems related to the equations of motion:

1.  A car starts from rest and accelerates at 5 m/s/s.  After 8 seconds of continual acceleration:

a.  how fast is it moving?
b.  how far has it gone?

(40 m/s, 160 m)

2.  If you were to drop a ball (from rest) from a 50-m tall tower, find:

a.  how long it takes to hit the ground?
b.  how fast it will be traveling right before it hits?

(3.19 seconds, 31.3 m/s)

3.  Think about question number 2 again.  This time, the ball is kicked horizontally from a 50-m tall tower at 20 m/s.

a.  how long will it take to hit the ground?
b.  how far (horizontally) will the ball travel
c.  What effect does the horizontal speed (20 m/s) have on this problem?

(3.19 s, 64 m)


Other things to review:

- Difference between velocity (or speed) and acceleration

- The correct units for velocity, distance, and acceleration

- The correct symbols for velocity, distance, and acceleration

- Graphs of motion and how to interpret them, specifically:
     a.  What does a linear graph of distance vs. time indicate (and what does the slope represent)?
     b.  What does an exponential graph of distance vs. time indicate?
     c.  What does speeding up vs. slowing down look like on a graph?

- Why didn't most people hit the target from the zip line?

- What is the difference between horizontal motion and vertical motion?