1. and Velocity
BHS-PS1-0
Level 3

3. a little review first………..
Wendy runs 200 m east on a straight road and then turns west and runs 100 m back. What would be the distance she traveled and her displacement?
distance = 300 m displacement = 100 m east
A bus goes 500 km east from town A to town B in the morning and comes back halfway in the evening travelling west. What is the distance and displacement of the bus?
distance = 750 m displacement = 250 m east
Ashley travels 5 mi N to the nearest gas station. She then continues traveling in the same direction another 15 mi. What is the distance and displacement?
distance = 20 miles displacement = 20 miles N

4. Speed is the distance traveled per unit of time. (SCALAR)
Speed (s) =
distance (d)
time (t)
Each variable measured by units:
Distance: meters (m), miles (mi)
Time:seconds (s), hours (hr), minutes (min)
Speed: meters per second (m/s),
miles per hour (mi/hr),
kilometers per hour (km/hr)

5. Using a formula triangle
Boardworks GCSE Additional Science: Physics
Speed and Acceleration
A formula triangle helps you to rearrange a formula. The formula triangle for speed (s), distance (d) and time (t) is shown below.
Cover the quantity that you are trying to work out, which gives the rearranged formula needed for the calculation.  x
So to find speed (s), cover up s…
…which gives the formula…
s = d t

6. Solving for speed: Step 1 Read the problem.
“A car traveled 110 miles in 2 hours. What is the speed?”
Step 1 Read the problem.
Formula
Plug-in
Answer
d =
t =
s =
Units, units, units!

7. ? “A car traveled 110 miles in 2 hours. What is the speed?”
Step 2 Write down what you know. GIVEN What are you trying to find? UNKNOWN
110 miles
2 hours
Formula
Plug-in
Answer
110 miles
d =
t =
2 hours
s = ?
Units, units, units!

8. FORMULA SHOULD MATCH THE UNKNOWN
“A car traveled 110 miles in 2 hours. What is the speed?”
Step 3 Set up the formula.
FORMULA SHOULD MATCH THE UNKNOWN  x
s = d t
Formula
Plug-in
Answer
110 miles
d =
t =
2 hours d t
s =
s = ?
Units, units, units!

9. ? “A car traveled 110 miles in 2 hours. What is the speed?”
Step 4 Plug-in the numbers. SUBSTITUTE AND SOLVE. CHECK UNITS
110 miles
2 hours
Formula
Plug-in
Answer
110 miles
d =
t =
2 hours d t
s =
110 mi
2 hr
s = 55
mi/hr
s =
s = ?
Units, units, units!

10. 1. If a car travels 400m in 20 seconds how fast is it going?
m/s
s =
2. If you move 50 meters in 10 seconds, what is your speed? d t
s =
50 m
10 s
s = 5
m/s
s =

11. 4. A plane travels 395,000 meters in 9000 seconds. What was its speed?
3. You arrive in my class 45 seconds after leaving math which is 90 meters away. How fast did you travel? d t
s =
90 m
45 s
s = 2
m/s
s =
4. A plane travels 395,000 meters in 9000 seconds. What was its speed? d t
s =
395,000 m
9000 s
s =
43.9
m/s
s =

12. Solving for time
“A runner’s average speed during the 10 kilometer race was 20 km/hr. What was his time?’”
CIRCLE AND LABEL INFO PROVIDED!
Step 1 Read the problem.
Formula
Plug-in
Answer
d =
t =
s =
Units, units, units!

13. Solving for time
“A runner’s average speed during the 10 kilometer race was 20 km/hr. What was his time?’”
Step 2 Write down what you know. GIVEN What are you trying to find? UNKNOWN
Speed of runner: 20 km/hr
10 km
Formula
Plug-in
Answer
10 km
d =
t = ?
s =
20 km/hr
Units, units, units!

14. Solving for time
“A runner’s average speed during the 10 kilometer race was 20 km/hr. What was his time?’”
Step 3 Set up the formula. FORMULA MUST MATCH UNKNOWN  x
Formula
Plug-in
Answer
10 km
d =
t = ? d s
t =
s =
20 km/hr
Units, units, units!

15. ? Solving for time Time = 0.5 Hour
“A runner’s average speed during the 10 kilometer race was 20 km/hr. What was his time?’”
Step 4 Plug-in the numbers. SUBSTITUTE AND SOLVE. CHECK UNITS
Time = 0.5 Hour
Speed of runner: 20 km/hr
10 km
Formula
Plug-in
Answer
10 km
d =
t = ? d s
t =
10 km
20 km/hr t = =
0.5 hr
10 km
20 km/hr
s =
20 km/hr
Units, units, units!

16. 1. How much time will it take for a bug to travel 5 meters across the floor if it is traveling at 1 m/s? d s
t =
5 m
1 m/s
t = 5 s
t =
2. You need to get to class, 200 meters away, and you can only walk in the hallways at about 1.5 m/s. (if you run any faster, you’ll be caught for running). How much time will it take to get to your class? d s
t =
200 m
1.5 m/s
t =
133.3 s
t =

17. 3. In a competition, an athlete threw a flying disk 139 meters through the air. While in flight, the disk traveled at an average speed of 13.0 m/s. How long did the disk remain in the air? d s
t =
139 m
13.0 m/s
t =
10.7 s
t =

18. Solving for distance
“You decide to go to Dallas to see friends. Your friends tell you that it takes 4 hours to get to Dallas at an average speed of 70 miles per hour. Approximately how many miles is it to their house?”
Step 1 Read the problem. ?

19. Solving for distance
“You decide to go to Dallas to see friends. Your friends tell you that it takes 4 hours to get to Dallas at an average speed of 70 miles per hour. Approximately how many miles is it to their house?”
Step 2. Write down what you know. GIVEN
What are you trying to find? UNKNOWN ? ?
d =
t =
s =
4 hrs
70 mi/hr

20.  x ? Solving for distance
“You decide to go to Dallas to see friends. Your friends tell you that it takes 4 hours to get to Dallas at an average speed of 70 miles per hour. Approximately how many miles is it to their house?”  x
Step 3 Set up the formula. EQUATION ?
d =
t =
s =
4 hrs
Formula
Plug-in
Answer
70 mi/hr
d = s * t
Units, units, units!

21. ? Solving for distance 280 mi
“You decide to go to Dallas to see friends. Your friends tell you that it takes 4 hours to get to Dallas at an average speed of 70 miles per hour. Approximately how many miles is it to their house?” ?
Step 4 Plug-in the numbers. SUBSTITUTE Do the math. SOLVE. ANSWER with correct unit.
280 mi ?
d =
t =
s =
4 hrs
Formula
Plug-in
Answer
70 mi/hr
d = s * t
d =70 mi/hr * 4 hr =
280 mi
Units, units, units!

22. 1. How far can you get away from your little brother with the squirt gun filled with paint if you can travel at 3 m/s and you have 15s before he sees you?
d = s * t
d = 3 m/s * 15 s 45 m
d =
2. How far can your little brother get if he can travel at 2.5 m/s and in 5 seconds you will discover that his squirt gun has run out of paint?
d = s * t
d = 2.5 m/s * 5 s
12.5 m
d =

23. Velocity

24. What is the difference between speed and velocity?

25. Velocity has speed & direction which means it is a VECTOR quantitiy
55 mi/hr
All of these cars had different velocities because they were traveling in different directions.
55 mi/hr
55 mi/hr

26. velocity (v) =
displacement (d)
time (t) d
d =
v * t v t
d v
t =

27. 1. The train traveled 500 kilometers north to Odessa in 2 hours
1. The train traveled 500 kilometers north to Odessa in 2 hours. What is the train’s velocity? d t
v =
500 km N
2 hr
v =
250
km/hr N
v =
2. The race car was moving for 3.7 hours and during that time moved 500 miles east. What is the velocity? d t
v =
500 mi E
3.7 hr
v =
135.1
mi/hr E
v =

28. 3. Mike is driving west on I-80 for 1
3. Mike is driving west on I-80 for 1.5 hours at a speed of 70 miles per hour. What is his displacement?
d = v * t
d = 70 mi/hr W * 1.5 hr
105 mi W
d =