Question

Activity 2 Compute for the following: Speed; Distance, Time

1. A car travels 300 kom in 6 hours. What is the average speed of the car in km/h?
Given
Solution
Car travels in 300 kom ( distance) in
6 hours (time)

2. What is the speed of a jet plane that flies 8100 kon in 9 hours? (in km/h)
Given:
Solution
Jet travels 8100 km (distance)in
9 hours (time)

3. A storm is moving toward your house at a speed of 20 kmh.it is now 60 km away from your house. In what time will the storm reach your house?
Given:
Solution:
Storm moving at 20 km/h (speed) at
60 kun (distance)
Speed and direction
In describing the motion of an object, we do not just describe​

Answer 1

1. 50 km/h

2. 900 km/h

3. 3 hours

Explanation:

1. The distance the car travels, Δd = 300 km

For how long it takes the car to travel the 300 km, Δt = 6 hours

Average speed,
`\overline v`, is given as follows;

`\overline v = (The \ total \ distance )/(The \ total \ time \ it \ takes ) = (\Delta d)/(\Delta t)`,

`\therefore \overline v = (300 \ km)/(6 \ hours) = 50 \ (km)/(hour)`

The average speed of the car,
`\overline v` = 50 km/h

2. The distance the jet plane flies, d = 8,100 km

For how long it takes the the jet plane to fly the 8,100 km, t = 9 hours

The speed, v, of the jet plane is given as follows;

`Speed, \ v = (Distance)/(Time) = (d)/(t)`

`v = (The\ distance \ the \ jet plane \ flies)/(The \ time \ it \ takes \ to \ fly \ thart \ distance ) = (d)/(t )`,

`\therefore v = (8,100 \ km)/(9 \ hours) = 900 \ (km)/(hour)`

The speed of the jet plane, v = 900 km/h

3. The speed of the storm, v = 20 km/h

The distance of the storm from the house, d = 60 km

The time 't' it takes the storm to reach the house is given as follows;

`Speed, \ v = (d)/(t)`

Therefore, by cross multiplying and dividing by 'v', we get;

`Time, \ t = (d)/(v)`

Plugging in the known values of 'd' and 'v' gives;

`Time, \ t = (60 \ km)/(20 \ (km)/(hour) ) = 3 \ km * (hour)/(km) = 3 \ hours`

The time it takes the storm to reach the house, t = 3 hours.