Steemkids math lessons|Speed, distance and time | 10% payout to @steemkidss

Hello dear fellow kids, it's another week and another exciting math lesson. This week's topic will be about Speed, time and distance.
Please carefully follow all the methods and solutions in this post.

_{designed in polish}

Speed is defined as the rate at which an object moves from a place to another or how fast something moves.
When we ride our bikes or walk to somewhere, our amount of speed may not be the same all the way. To be able to know how long a journey will take we need to be able to calculate average speed and that is the essence of this lesson.

Average speed

Average speed of an object means the rate at which it covers a distance.
Common unit of speed is kilometer per hour(km/hr). For smaller measurements we can also use metres per second (m/s) and centimeters per second(cm/s).

If a bus travels at a rate of 50 kilometers in 1 hour we write that the average speed is 50 km per hour, or 50 km/hr.

Average speed is expressed as the distance covered and time.
The formulary for speed is:
Average speed = distance/time

Example

Fredrick travel a distance of 10 km in 2 hours. What is his average speed.

Solution
Distance = 10 km
Time = 2 hours
Input formular

Average speed = total distance/total time

Replace the formula with the values for each
Represent average speed with A.s.

A.s = total distance = 10/total time = 2

A.s = 10/2
A.s = 5.
Fredrick covered the distance of 10km in 2hours at the average speed of 5 km/hour.

Example 2

A hare runs 12km in 30mins while a horse runs 20 km in 10 mins.

• Calculate the speed of each animal

Solution

Speed of each animal
The hare
Distance run = 12km
Time taken = 30 minutes
Note that the time taken is not the standard unit; that is, the hour. It needs to be converted to minutes.
We divide by 60 when converting minute to hours.
So:
30/60 = 1/2 or 0.5
The time taken is now 1/2 or 0.5

Speed = distance travelled/time taken = 12/0.5
S = 12/0.5 = 24
Speed of the hare = 24km in 30mins.

The horse
Distance run = 20km
Time taken = 10 mins.

Change minutes to hour
20/60 = 1/3

The time taken is now 1/3

Speed = distance/time = 12 ÷ 1/3
12 ÷ 1/3 = 12 × 3/1
12 × 3/1 = 36/1 = 36

The speed of the horse is 36km in 10 mins.

Example 3

A cyclist travelled 16km in 2 hours. At what speed did he travel?
Distance travelled = 16km
Time taken = = 2 hours

Speed = distance/time
Speed = 16km/2hr = 16/2 = 8/1

The speed = 8km/hr.

distance

We can derive the formula for distance and time using the formula for speed.

To derive the formula for distance we simplify the former formula.

Example

Let's solve for distance now...

Question 1

A vehicle travels at an average speed of 24km/hr for 4 hours, What is the distance covered by the vehicle.

Solution

Average speed = 24km/hr
Time taken = 4 hours
Distance travelled = Average speed × time taken
24 × 4 = 96km.

Time

We also derive the formula for time from the formula for speed.
Below is the example of how to do it

Let's solve for speed:

Question

An airplane flies 2800km at a speed of 700km/hr. How long is the flight?

Solution

Distance traveled = 2800km
Speed = 700km/hr
Time taken = distance travelled/speed
= 2800/700 = 28/7 = 4
Time taken = 4 hours.

Assignment

• Derive the formula for Time and distance using the formula for speed.(show full working)

• Find the time taken by a bus to travel a distance of 625km with an average speed of 25km/hr

• A cyclist travels at a distance of 48km in 1 hour. How far will he travel in 7 hours

• A motorist travels 20km in 4 hours. At what speed did he travel?

Rules

All assignments will be submitted as a comment under this post.

You are expected to add at least one photo of you solving the questions and also a photo of the work done.

This assignment is only for verified kids in steemkids community.

Duration

Entry will be accepted until after 7 days.

Reward

Each participant will receive one steem from @steemkidss.