Archive for the ‘units length’ Category

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8c. What Volume of Alcohol is Lethal?

August 14, 2017

The Complaint

8c: I Will Never Use this Maths

The Solution:

You are going to use this maths NOW……………..

……………………………………………………………………..

How much alcohol will kill you?

TOPICS: Decimals, %, algebra, vol, weight units (Metric)

At low levels of consumption alcohol impairs decision making and inhibits coordination. It makes you DUMB and CLUMSY, which can cause serious injuries if you, say, fall down stairs.

Legal Age to Buy or Sell Alcohol USA: 21 years

Legal Age to Buy or sell Alcohol AUST, NZ & UK: 18 Years

Legal Age to Buy or sell Alcohol CANADA: 18 – 19 Years depending on region.

At higher levels of consumption ALCOHOL can kill. It is a depressant. It acts on your central nervous system. It can STOP YOU BREATHING.

WORKSHEET PDF:  How Much Alcohol Would Kill You? WORKSHEET

WORKED EXAMPLE

1. Calculate the weight of (pure) alcohol or ethanol in the following standard drinks using the following information:

Now Ethanol =  0.79 gm/ml

More information @ alcohol.org.nz

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9. I Hate Answering Questions in Class: BUSTED

August 10, 2017

The Complaint:

 

9. I Hate Answering Questions in Front of the Class

 

The Cause:

Students worry about getting the answer wrong in front of the class because they believe that maths answers are always either RIGHT or WRONG.

The Solution:

The maths we need in the REAL world often involves open ended questions. Think of finding directions on Google Maps. What is the best way to get from A to B? One route might be shorter but include tollways another might involve longer distances but less traffic. 

Text book problems are often repetitive with RIGHT answers at the back of the book. But in the real world maths problems nearly always involve THINKING. eg. A building design might require specific engineering maths. Now add costing! That’s an open question. There are many options. Maybe the costing will then change the engineering. Build 20 stories instead of 25.

Thinking Outside the box in Education: Info and Toolbox: here

Prof Peter Liljedahl, Faculty of Edu, Simon Fraser Uni, Canada, advocates  open ended questions in the maths classroom.

Here are some of his examples for Year 7 -9 (Download pdf file at the link):

Concert in Toronto;

You have won tickets to a concert in Toronto but must plan your trip using flight times to arrive at the concert by 9pm.

Two Bike Race:

You are in a bike race and have to use a street bike and trail bike, but one bike must be left somewhere on the route.  You travel at different speeds depending on which bike you use. What route do you take? (A basic map is included.)

Something inspiring:

Maths is often about playing around with answers. This is how play led a class of 12 year olds to produce a peer reviewed research paper published in a science journal.

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The Terrifying Maths of Running from a Bear … Metric Units

July 17, 2017

METRIC 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.

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The Terrifying Math of Running from a Bear … USA Units

July 17, 2017

USA 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.

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Parabolas and the Art of Spitting

May 5, 2017

The maths that proves that the 45 degree angle is the angle that produces the maximum distance travelled is quite tricky and involves trigonometry. But this just shows how cool maths can be. See the full calculations here.

More long bow maths here at ROBINHOOD GIVE US YOUR BEST SHOT

Interesting maths work on WHICH SPORT IS MORE DANGEROUS, BASEBALL OR CRICKET? here.

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World Record Watermelon Seed Spitting Maths

May 5, 2017

Here are some worksheets on MEAN, MEDIAN and MODE for middle school students. It also involves work with units (Metric/USA). But these are real numbers and the distances that 14 year olds can spit watermelon seeds is amaaaazing!

You can find the free pdf worksheets  (included below) here.

Other fun middle school math(s) worksheets in the Hot Heels series at TpT include Unit Rates, Angles, Ratios and Algebra.

Ask volunteers to see how far they can spit a seed. (WARNING: The volunteer must breath in through their nose before they spit. You don’t want them inhaling a seed.)

ANSWER SHEETS

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

February 3, 2017
NIce Truck Attack 2016 The Independent, UK

Nice Truck Attack 2016 The Independent, UK

Berlin Christmas Maraket Attack 2016, ABC

Berlin Christmas Maraket Attack 2016, ABC

Melbourne Car Attack 2017

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.

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How do you escape a car travelling at 60 kph towards you when you are less than 9 m away?

Jump upwards!

You might reduce the impact and even go over the roof.

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