Velocity Guided Notes 10/20/20

Velocity Guided Notes

Definition and Calculation

Multiple Choice

If something has magnitude (a number amount) and a direction, it is called a...

• vector

• kilometer

• acceleration

• force

Explanation on Writing Division and Fractions

• Fractions and division are the same thing

•  $\frac{1}{2}=$  1 divided by 2 and that equals 0.5 because 0.5+0.5=1

The division sign can also be pronounced as "per"

• Example: If we have 8 slices of pizza and 4 people, then we need to DIVIDE the pizza evenly so everybody gets the same amount.

•  $\frac{8slices}{4people}=\frac{2slice}{1person}=$  2slices/person

• 8slices per 4people = 2 slices per 1 person = 2slices per person

Multiple Select

You have a package of Starburst to split with your friend. There are 10 pieces. How many ways can you express this. Choose all that are correct.

• 10 pieces per 2 people

• 5 pieces per person

•  $\frac{10\ pieces}{2\ people}$  

• 5 pieces/person

Velocity Definition

• speed is distance in a given amount of time, like 60 miles per hour

• velocity is speed in a given direction

• Ex: 5m/s north, +60mph, -60mph, 10ft/min down

• it is a vector

Multiple Select

Which one of these is not an example of velocity? Check all that apply.

• 55 miles per hour

• 6 m/s west

• 3 feet

• -20 kilometers per second

Velocity Definition Continued

• the change in position (displacement) in a given amount of time

• Ex: If it takes 1 minute for me to walk 100 feet to the right, then my velocity is 100 feet per 1 minute.

• Ex: 100 feet per minute or 100ft/min

Calculations

• Let's say that I walk 200 feet in 2 minutes. How would we say that?

• Formula for velocity:

• displacement divided by change in time

• v=Δd/Δt

Calculations Continued

• I walk 200 feet in 2 minutes

• Δd = 200 feet

• Δt = 2 minutes

•  $\frac{\Delta d}{\Delta t}=\frac{200ft}{2\min}=\frac{100ft}{1\min}=$  100ft/min

Multiple Choice

I get on the track and run 100 meters in 10 seconds. What is the distance traveled?

• 100m

• 10s

Multiple Choice

What is the change in time?

• 100m

• 10s

Multiple Choice

Using v=Δd/Δt how would I solve for velocity in my 100m in 10s problem?

• 10s/100m

• 100m x 10s

• 100m/10s

Solution

• Velocity = change in distance/change in time

• v=Δd/Δt

• v = 100m/10s

• v = 10m/1s or 10m/s

Displacement (or Distance) formula

• The formula v=d/t can be rearranged

• vt = d

• Example 60miles per hour x 2 hours = 120miles traveled.

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