Question

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

Answer 1

Answer:

1. 50 km/h

2. 900 km/h

3. 3 hours

Step-by-step 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;

$\overline v = \dfrac{The \ total \ distance }{The \ total \ time \ it \ takes } = \dfrac{\Delta d}{\Delta t}$,

$\therefore \overline v = \dfrac{300 \ km}{6 \ hours} = 50 \ \dfrac{km}{hour}$

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;

$Speed, \ v = \dfrac{Distance}{Time} = \dfrac{d}{t}$

$v = \dfrac{The\ distance \ the \ jet plane \ flies}{The \ time \ it \ takes \ to \ fly \ thart \ distance } = \dfrac{d}{t }$,

$\therefore v = \dfrac{8,100 \ km}{9 \ hours} = 900 \ \dfrac{km}{hour}$

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;

$Speed, \ v = \dfrac{d}{t}$

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

$Time, \ t = \dfrac{d}{v}$

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

$Time, \ t = \dfrac{60 \ km}{20 \ \dfrac{km}{hour} } = 3 \ km \times \dfrac{hour}{km} = 3 \ hours$

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