average speed

1. Average Speed
Average speed indicates the average rate of
movement during the entire time of the travel (t)
throughout the entire distance traveled (d). It uses the
formula:
average speed =
𝐭𝐨𝐭𝐚𝐥 𝐝𝐢𝐬𝐭𝐚𝐧𝐜𝐞 𝐭𝐫𝐚𝐯𝐞𝐥𝐞𝐝
𝐭𝐨𝐭𝐚𝐥 𝐭𝐫𝐚𝐯𝐞𝐥 𝐭𝐢𝐦𝐞

2. Sample Problem
1.) The cheetah, considered the fastest land animal, can travel
625 m in 25.0 s. what is its average speed?
Given: d = 625 m
t = 25 s
Required: average speed
Solution: average speed =
𝐭𝐨𝐭𝐚𝐥 𝐝𝐢𝐬𝐭𝐚𝐧𝐜𝐞 𝐭𝐫𝐚𝐯𝐞𝐥𝐞𝐝
𝐭𝐨𝐭𝐚𝐥 𝐭𝐫𝐚𝐯𝐞𝐥 𝐭𝐢𝐦𝐞
=
𝒅
𝒕
=
𝟔𝟐𝟓 𝒎
𝟐𝟓.𝟎 𝒔
= 25.0 m/s

3. 2.) How far can the cheetah in the previous problem go in one
minute?
Given: v = 25 m/s
t = 1.00 min = 60.0 s
Required: d
Solution: Note that the problem gives the time in minutes, but
the speed obtained from the first problem is given in
meter per second. It is important that your units agree
with each other. Since 60 seconds is equal to 1 minute,
distance = speed x time
d = vt

4. distance = speed x time
d = vt
= 25.o
𝑚
𝑠
x 60.0 s
= 1 500 m
If the cheetah runs at 25.0 m/s, it can cover a
distance 0f a 1 500 m in one minute.

5. 3.)How long will it take the cheetah to run a distance of 5.0 km
if it runs at an average speed of 25 m/s?
Given: v = 25 m/s
d = 5.0 km
Required: t
Solution: Note that the problem gives the distance in
kilometers but the speed is in meters per second. Again,
make sure that your units agree with each other.
Converting distance into meters.
5.0 km
1 000m
1km
= 5 000 m

6. time =
𝐝𝐢𝐬𝐭𝐚𝐧𝐜𝐞 𝐭𝐫𝐚𝐯𝐞𝐥𝐞𝐝
𝐬𝐩𝐞𝐞𝐝
t =
𝒅
𝒗
t =
𝟓 𝟎𝟎𝟎𝒎
𝟐𝟓𝒎/𝒔
t = 𝟐𝟎𝟎 𝒔
If the cheetah runs at 25 m/s. it will take the cheetah
200 s to cover 5 km.

7. Solve the following:
1. Usain Bolt, a Jamaican sprinter, holds the Olympic and
world records for the 100-m dash, which he achieved
during the 2008 Summer Olympics in Beijing, China. He
finished the 200-m dash in 19.30 seconds. What was his
speed?
2. If a driver takes 30 min to get to the town market, which
is 1.5 km away from your house, what is his average
speed?
3. If a bus travelling at 69 km/h will cover a distance 0f 600
km, how many hours will it take to reach its destination?

8. Velocity
- it is similar to speed except that it not only tells how fast
or how slow a motion is; it also indicates the direction. Velocity
is a vector quantity. Vector quantity describe both magnitude
and direction.
Distance
- is simply the length between two points.
Displacement
- is another vector quantity that indicates both the distance
and the direction of motion.
- It tells how far and where you are from the starting point.

9. Direction: Identify the following quantities if it is a
vector or a scalar quantity.
1.) 200 kg of meta 6.) 10 km to the north
2.) 200 N of falling bag 7.) a boy pushes a chair
3.) 9.8 m/s2 due to gravity 8.) 70 km/hr 45ᴑ
4.) A girl is walking at 9.) 100 m
200 m/s
5.) a dog running 28 km/hr 10.) Sandi traveled 200
km in two hours
going to school

10. Practice Exercise:
Solve for the missing variable.
v
(m/s)
t
(s)
d
(m)
40.0 40.0 1600
2.8 50.0 140
23.6 830