1. Physics Quiz problem #3

2. The problem….
How far will an object, initially at rest, in
free fall have traveled by the time it’s
instantaneous velocity reaches 20 m/s?
* Ignore air resistance
**Use gravity = 10 m/s2

3. Step 1: Draw a picture
object Vinitial is at rest, or Vinitial = 0 m/s
Gravity accelerates object
at 10m/s2
object Vfinal = 20 m/s

4. Step 2: Write down what you know
Vinitial = 0 m/s
Vfinal = 20 m/s
Acceleration, or a = 10 m/s2

5. Step 3: Identify relationships we
know

6. We were looking for….

7. Don’t forget the other guys

8. Step 4: Fill in the numbers

9. Step 4 continued…

10. The little things~
Hopefully you noticed that the units worked out for
when we solved for time and for distance….
So on to the next step~

11. Step 5: Reality Check!
Does the answer you found make sense?
This is where you consult your everyday experiences
and make sure your answer can actually happen.

12. Congratulations!
We solved the problem! Physics models everyday
occurrences so your answer should make sense.

13. Try this at home
The same object is in free fall once again. Ignoring air
resistance, how far has an object at rest traveled from
when it reaches a final instantaneous velocity of 30
m/s?
Check your work, the answer is 45 meters