14-calculating Speed Notes

Name: ________________________________________

Class: ________

Date: _______

Calculating Speed Notes

Speed:  Speed – is the rate at which an object _______________.  Speed depends on ___________________ and ____________________.  Speed is the _______________ of time it takes to go a ______________ distance.  The SI unit for speed is ______________________ or m/s.  The formula for calculating speed is: distance ______________ by time. d  S= t ************************************************************************************

5 Steps to solve a Speed Word Problem:

There are 5 steps you use when calculating speed. You must use all 5 steps and neatly show all 5 steps. When your work is graded, a majority of the question will depend on how you set up the problem, not the final answer you get. Box the final answer. Step 1: In the word problem underline what is given. Step 2: In the word problem CIRCLE what you will be solving for

Step 3: WRITE THE FORMULA

Speed = distance time

Step 4: FILL IN VARIALBES

Speed = 500 m

Step 5: WRITE THE ANSWER With Correct Units

Speed = 20 m/s

25 s

Name: ________________________________________

Class: ________

Date: _______

Guided Practice: A car travels 80 km in 2 hours. What is the car’s speed? Speed = distance Time

S=d t

Speed = ________

Speed =

Independent Practice: 1. A car travels 50 km in 0.5 hours. What is the car’s speed?

2. If an air plane travels 100 meters in 20 seconds, what is the car’s speed?

3. Darla rollerblades to her friend’s house. Her friend lives 105 meters south, and it took Darla 15 seconds to get there. What was her speed?

4. A Cardiff student practicing for a track meet ran 240 meters in 30 seconds. What was his speed?

Name: ________________________________________

Class: ________

Date: _______

Calculating Average Speed: This is the same as calculating speed, except you must find the total distance and divide it by the total time. Step 1: In the word problem underline what is given. Step 2: In the word problem CIRCLE what you will be solving for. Step 3: WRITE THE FORMULA.

Average Speed = total distance total time

Step 4: FILL IN THE VARIABLES.

Average Speed = 200m + 300m = 500m 10 s + 15 s 25 s

Step 5: WRITE THE ANSWER Average Speed = 20 m/s With Correct Units. ************************************************************************************ Guided Practice: You walk 200 meters from your 4th period class to the cafeteria in 2 minutes, 50 meters from the cafeteria to the restroom in 1 minute, and then 75 meters from the restroom to your 6 th period class in 2 minutes, what is your average speed? Average Speed = total distance total time

Avg. S = total d total t

Average Speed = _______________ Average Speed = Independent Practice: 1. Calvin rode his bike to his friend’s house 500 meters away in 2 minutes, he then rode to the pool 200 meters away in 1 minute, and at last he rode 620 meters home in 2 minutes. What is Calvin’s average speed?

Name: ________________________________________

Class: ________

Date: _______

2. A bus travels from Cardiff Junior High school to HEB, a distance of 18 miles in 45 minutes. It remains at HEB for 30 minutes at rest. The bus then travels from HEB to Toys-R-US, a distance of 5 miles, in 55 minutes. What was the average speed for the trip (total distance/ total time)?

3. It is now 8:59 am, but when the bell rings at 9:00 am Samantha will be late for Science class for the third time this week. She must get from one side of the school to the other by hurrying down three different hallways. She quickly walks down the first hallway, a distance of 35.0 m, in 15.5 seconds. The second hallway is filled with students, and she covers its 48.0 m length in 13 seconds. The final hallway is empty, and Samantha speed walks its 60.0 m length in 10.5 seconds. What was Samantha’s average speed as she travelled through the hallways?