July 17, 2017

# Grizzly Bear

Weight:  550 lb

Height:  8’ 2”

Top Speed: 35 mph  =   51 ft/s

# Brown Bear

Weight:  1,500 lb

Height:  8’ 2”

Top Speed: 22 mph  =  32 ft/s

Comparing these speeds to the fastest man on earth, Usain Bolt:

## Usain Bolt:

Top speed: 27 mph  =   40 ft/s

# Bears are not dangerous:

………………………………………………………………………

In fact, more Americans die each year from choking on their own vomit than are killed by bears.

More death stats here

Nevertheless, bears are very fast. So you can see why Park Rangers offer the following advice:

The reason for waiting until the bear is 15 ft away is to make sure the spray doesn’t disperse in the air. If the Pepper Spray is too spread out it will not stop the bear.

## The Simple Maths of a Car used as a Weapon … METRIC units

February 3, 2017

Nice Truck Attack 2016 The Independent, UK

Berlin Christmas Maraket Attack 2016, ABC

Melbourne Car Attack 2017.

Cars (and trucks) have been used as weapons by drivers purposefully driving into crowds including:

2014: Saint-Jean-sur-Richelieu, Quebec

2014 : Jerusalem, Israel.

2016: Nice, France

2016: Berlin, Germany

2017: Jerusalem, Israel

2017: Melbourne, Australia.

## What does the maths tell us?

Melbourne is Mathspig’s home town. The car attack killed, tragically, 6 people and injured many more. The question many seem to ask is:

## Why can’t people get out of the way?

Look at the video below of the Melbourne car. It doesn’t appear to be going that fast. But the maths tells a different story. You need quite a distance between you and a car travelling at approx 60 kph to have enough time to run clear. (See calculations below)

## How fast do you react?

We will set your reaction time at 0.4 sec. This allows time for you to react and turn. If you want to test your reaction time go here. But remember you have to turn as well.

## How fast would you run?

According to the Telegraph, UK, the average human can run at 15.9 mph (25.6 kph) and the National Council of Strength and Fitness 15 mph (24.1kph), which Mathspig has rounded off to 25 kph.

# Jump upwards!

## The Simple Math of a Car used as a Weapon … USA units

February 3, 2017

Nice Truck Attack 2016 The Independent, UK

Berlin Christmas Maraket Attack 2016, ABC

Melbourne Car Attack 2017.

Cars (and trucks) have been used as weapons by drivers purposefully driving into crowds including:

2014: Saint-Jean-sur-Richelieu, Quebec

2014 : Jerusalem, Israel.

2016: Nice, France

2016: Berlin, Germany

2017: Jerusalem, Israel

2017: Melbourne, Australia.

## What does the math tell us?

Melbourne is Mathspig’s home town. The car attack killed, tragically, 6 people and injured many more. The question many seem to ask is:

## Why can’t people get out of the way?

Look at the video below of the Melbourne car. It doesn’t appear to be going that fast. But the math tells a different story. You need quite a distance between you and a car travelling at approx 35 mph to have enough time to run clear. (See calculations below)

## How fast do you react?

We will set your reaction time at 0.4 sec. This allows time for you to react and turn. If you want to test your reaction time go here. But remember you have to turn as well.

## How fast would you run?

According to the National Council on Strength and Fitness the average human can run at the speed of 15 miles per hour for short periods of time.

# Jump upwards!

## Dangerous Maths 3: Shark Attack

July 31, 2015

Aussie Pro surfer, Mick Fanning, grabbed world attention when he was attacked by a shark in the Fanning J-Bay Open, South Africa on Sunday 19 July, 2015. Fanning was knocked off his board and forced to fight for his life. He survived. News.com

One shark expert suggested the shark was a young great white shark under 3.5 metres.

# How fast can a shark swim?

According to the Smithsonian National Museum of Natural History:The torpedo shape of the great white is built for speed: up to 35 miles per hour (50 kilometers per hour). And then there are the teeth — 300 total in up to seven rows.

# How fast can you swim?

According to Junior Olympic Games Qualifying Times 2015

For 13-14 yo 100m freestyle:

t girl = 1.15 or 75sec

t boy =1.10. Or 70 sec

Lets assure you are an average swimmer but highly motivated on seeing a shark:

t kid = 100 secs

So you can swim 100m in 100 sec. But will you survive??????

Surf Lesson Bluey’s Beach NSW 2009

We’re sooo tough in Australia! Shark, Smark! Whatever.

Picture from Daily Telegraph

Also according to the Smithsonian: Sharks can detect both the direction and amount of movement made by prey, even from as far as 820 feet (250 meters) away.

But there is hope as, according to the National Geographic Channel, Most shark attacks occur less than 100 feet or 30.5 m from the shore mainly around popular beaches in North America (especially Florida and Hawaii), Australia, and South Africa.

Again we will assume that the swimmer is 30m offshore when he sees the shark fin 250m away. But this time we will have the world’s fastest swimmer. This time we are talking Dav vs Shark!!!!!!!!!