Examples with solutions for Average Speed: Applying the formula

Exercise #1

What is the average speed according to the data?

Travel time: km/h: distance:
3 - 70 - 210
1 - 40 - 40
2 - 0 - 0
2.5 - 100 - 250

Video Solution

Step-by-Step Solution

Let's first remind ourselves of the formula for finding velocity:

V=xt V=\frac{x}{t}

x x = distance
t t = time
V V = velocity

Then substitute the data into the formula:

V=210+40+0+2503+1+2+2.5 V=\frac{210+40+0+250}{3+1+2+2.5}

Calculate accordingly to get:

V=5008.5=58.82 V=\frac{500}{8.5}=58.82

Therefore, the average velocity is 58.82.

Answer

58.82....

Exercise #2

A man drives for two hours at a speed of 78 km/h, stops to get a coffee for fifteen minutes, and then continues for another hour and a half at a speed of 85 km/h.

What is his average speed?

Video Solution

Step-by-Step Solution

In the first stage, we want to find the distance the truck traveled in its total journey,

We will use the data we already have,

78 km/h for two hours of driving and 85 km/h for an additional hour and a half.

78*2+85*1.5=

156+127.5=

283.5 km

Now, we want to discover the total duration of the journey.

We know there were two hours of driving, a quarter-hour break, and another hour and a half of driving,

Meaning:

2+0.25+1.5=

3.75 hours

Now, we'll divide the travel distance by the number of hours

285/3.75=

75.6 km/h

And that's the average speed!

Answer

75.6 75.6 km/h

Exercise #3

In a relay race, three runners run one after another on a 450-meter track.

The first runner finishes in 1.5 minutes.

The second runner finishes in 1.35 minutes.

The third runner finishes in 1.42 minutes.

What is the average speed of the relay runners?

Video Solution

Step-by-Step Solution

Answer

5.3 5.3 meters per second

Exercise #4

A truck driven by George makes its journey in two parts.

In the first part, its speed is 82 km/h and it travels for 4 hours.

Then, George has a break at a petrol station for 20 minutes.

In the second part, George travels at a speed of 70 km/h for 3 hours.

What is his average speed?

Video Solution

Answer

73.36 73.36 km/h

Exercise #5

Gerard rides a motorcycle for 30 minutes over a distance of 40 km and continues for another 20 minutes at a speed of 70 km/h.

What is his average speed?

Video Solution

Answer

76 76 km/h

Exercise #6

A snail crawls for 7 minutes at a speed of 4 cm per minute, rests for 3 minutes, then continues to crawl a further 30 cm in 12 minutes.

What is its average speed?

Video Solution

Answer

2.64 2.64 cm per minute

Exercise #7

Hugo participates in a swimming competition where he must swim 4 lengths of 25 meters.

He completes the first 25 meters in 43 seconds.

He swims the second length at a speed of 0.75 meters per second.

Then he stops to rest for 4 seconds, before finishing the last two lengths in 89 seconds.

What is his average speed?

Video Solution

Answer

0.59 0.59 meters per second

Exercise #8

Gary runs at a speed of 2 meters per second for 2 minutes, then stops for a minute and runs again for 2 minutes at the same speed.

What is the average speed?

Video Solution

Answer

1.6 1.6 meters per second

Exercise #9

Jonathan is reviewing his cycling records from his last competition.

During the first half hour, he rode at a speed of 28 km/h.

The following two hours, he rode at a speed of 24 km/h, then 15 minutes downhill at a speed of 32 km/h, before continuing for another hour at a speed of 27 km/h.

What was his average speed?

Video Solution

Answer

25.888...

Exercise #10

Hugo jogs around a circular path with a diameter of 750 meters 7 times.

The first two times he did it in 1012 10\frac{1}{2} minutes.

For the next three laps, his speed is 9 km/h.

The last two laps takes him 12 minutes to complete.

What is the average speed?

Video Solution

Answer

10.732 10.732 km/h

Exercise #11

A projectile is fired at a speed of 2500 km/h and travels 135 meters until it hits its target.

It passes through the target, which reduces its speed to 1300 km/h, after which point it continues for another 1.8 seconds until it hits a wall.

What is its average speed from the moment of firing until it stops?

Video Solution

Answer

248.75 248.75 meters per second