Posts Tagged ‘Math %’
Have Yourself a Mathsy Little Christmas
December 5, 2019It is Xmas … Ah! The Joy of Algebra!
December 5, 2019
Great Math Xmas Ornament Ideas for Middle School here @ MathEqualsLove blog.
Mathematicians can make mountains out of mince pies, but in this case Dr Eugenia Cheng, who is Professor of Pure Mathematics at the University of Sheffield, UK, makes it look fun. The video clip includes some great Middle School Maths that you can eat.
Dangerous Math: Would You Survive a Shark Attack
July 5, 2019Aussie 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 m or 12 ft.
Would you survive a shark attack?
Let’s do the maths.
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 or 328 ft freestyle:
t girl = 1.15 or 75sec
t boy =1.10. Or 70 sec
Let’s assume you are an average swimmer but highly motivated on seeing a shark:
t kid = 100 secs
So you can swim 100m (328 ft) 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.
If average swimmer Dav is 100 ft (30 m) offshore and starts swimming when he sees the shark 820 ft (250 m) away, he would swim 63 ft (19.2 m) before the shark attacked. He is still 37 ft offshore. He might make it to shallow water. Or not!!!!
A Shark vs the World’s Fastest Swimmer
Again we will assume that the swimmer is 30m ( 100 ft) offshore when he sees the shark fin 250m (820 ft) away. But this time we will have the world’s fastest swimmer. This time we are talking Dav Holmes vs Shark!!!!!!!!!
If world champion swimmer Dav starts swimming when he saw the shark 820 ft (250 m) away, he would swim 163 ft (49.6 m) before the shark attacked. He would easily make it to shore before an attack. Dav would be swimming on sand.
The Terrifying Math of Running from a Bear … USA Units
May 14, 2019USA UNITS below. METRIC UNITS here.
BEAR STATISTICS
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:
More information at Mountain Nature.
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.
Ref: Dog helps save hikers after grizzly chases them for 20 minutes.
The Terrifying Maths of Running from a Bear … Metric Units
May 14, 2019METRIC UNITS below. USA UNITS here.
BEAR STATISTICS
Grizzly Bear
Weight: 250kg
Height: 250cm
Top Speed: 56kph = 16 m/sec
More bear stats here.
Brown Bear
Weight: 680kg
Height: 250cm
Top Speed: 35kph = 10m/s
More bear stats here.
Comparing these speeds to the fastest man on earth, Usain Bolt:
Usain Bolt:
Top speed: 243kph = 12m/s
So Usain Bolt could out run a Brown Bear but NOT a Grizzly!
Bears are NOT as dangerous as:
In fact more Americans die choking on their own vomit each year than a re killed by bears.
More death stats here.
But bears are very fast so Park Rangers recommend the following survival tactics:
More bear survival info here.
REF: Dog helps save hikers after grizzly chases them for 20 minutes here.
Medals, Meglomaniacs and Sharp Shooters…….. The Math USA units
May 8, 2019When Mathspig recently saw images of some Russian soldiers covered in medals it prompted the question
‘Could medals protect the wearer from a sharpshooter?’
Mathspig was interested in this question because megalomaniac military dictators who take over countries by force tend to award themselves lots of medals. But they are also likely to be the target of sharpshooters from a liberation movement.
The target zone (circle) had a diameter of 0.7 inches. This is smaller than the diameter of an American Quarter, an Australian 10c and a UK pound all of which have a diameter of approx 0.96 inches.
So the megolmaniac military dictator wins!!! He IS protected – on his chest – by his medals!!!!!! Unless the sharpshooter manages a ‘lucky’ shot.
Giant Easter Egg Math … USA units
April 5, 2019Good News for Chocoholics
To get the right texture Easter Eggs are made from sugar or sucrose and not from corn syrup. But chocolate contains lots and lots of sugar.
………………………………………………..
Guylian Sea Shells:
Weight Sea Shell: 4.23 oz
Weight Sugar: 1.69 oz
% sugar = 1.69/4.23 x 100 = 40%
………………………………………………………………..
………………………………………………………………
This is a Guylian Luxury Easter Egg. It can also be used as a designer handbag, I guess.
Guylian Easter Eggs:
Weight Easter Egg: 3.53 oz
Weight Sugar: 1.83 oz
% sugar = 1.83/3.53 x 100 = 52%
You’ll find nutrition data here.
…………………………………………………….
……………………………………………………………….
