1. Unit Conversions

2. Objectives Learn how to convert units by using know conversion ratios.
Apply these conversions to answer questions.

3. Converting Units Why do we convert units?
We are needy people and try to always get what we want.
Also physics doesn’t work if you use the wrong units

4. The basics Converting prefixes Example 15kg to g 1302mL to L 15,000g

5. The next level Converting between systems
They (me) will give you the ratio before asking you to do this
Example
Convert 3 miles to meters (1 mile is meters)

6. Practice Convert 2.5 miles to meters (1 mile is 1609.34meters)
Convert 6 miles to km (1 mile is meters)

7. With a partner Convert 3 weeks into hours 3,600 seconds to hours
1,200 yards to feet

8. The next next level 400 feet per second to m/s (1 meter is 3.28 feet)
Convert 60 mph to m/s (1 mile is meters)
400 feet per second to m/s (1 meter is 3.28 feet)
30mph to km/h ( 1 mile is meters)

9. Partner Practice
Convert the following speeds. Show all units as well as cancellations.
a) 25 km/h to m/s
b) 150 km/h to m/s
c) 2.0 m/s to km/h
d) 50 m/s to km/h

10. Answers
a) 6.9 m/s
b) 41.7 m/s
c) 7.2 km/h
d) 180 km/h

11. The next next next level
a) The maximum speed reached by a standing skateboarder is about 14.7 m/s. Would the skateboarder get a ticket in a 30 km/h speed zone?
b) A snail crawls 100 times slower than a normal human walk (3 km/h). How many times slower than the skateboarder is the snail?

12. Answers
a) yes, speed of 52.9 km/h
b) 1763 times slower

13. Checkpoint
Can you apply your knowledge of unit conversions to solve more complex questions?