## 5. You can jump out of an airplane that is about to crash and catch the baddie who took the last parachute.

May 24, 2023

The names Bond, James Bond. In Moonraker  with Roger Moore (1979) 007 jumps out of a plane without a parachute to avoid an assassination attempt. He catches up with, Jaws, arch-baddie, in mid-air and takes his parachute. Jaws survives his fall by landing on a big top circus tent.

In Point Break with FBI agent Johnny Utah, Keanu Reeves, leaps from a skydiving plane after Patrick Swayzes’ characer, Bohdi, who has taken the last parachute. Utah catches Bohdi in mid-air, and after a tense confrontation with a gun, both survive using Bodhi’s chute. The remake was in 2015.

There are more movie and real life stories at the  Free Fall Maths link.

Note: We’ll assume Bhodi and Utah have equal horizontal velocities (plane exit velocity plus wind) so the following calculations only involve the vertical or falling velocity. The terminal velocities used for Bhodi and Utah are realistic estimates.

## 7. You can safely jump from a burning skyscraper/bridge/aircraft into water.

May 17, 2023

Angels and Demons (2009) Tom Hanks character, Robert Langdon, hero of Dan Brown’s jumps from a helicopter and falls thousands of feet into Rome’s Tiber River and survives, of course.

Ahhhh! Look up. It’s raining Tom Hanks!!!!!The Hulk (2003) The Hulk hops from the Golden Gate bridge onto a jet fighter, whose pilot tries to get rid of him at high altitude. The Hulk falls off and plummets many thousands of feet into the bay. He survives.

There are 2 factors we must consider when jumping or diving from a great height:

1. Surface Impact

2.Water depth

# 1. Surface Impact

According to the Free Fall website falling into water is not a good survival strategy.

‘Someone falling without a parachute from more than 2,000 feet or so would be falling quite a bit faster than 100 miles per hour (161 kph) The folks who have survived falls into water have had streaming parachutes above them, which probably slowed their falls to the 60 mph range (97 kph). Having a streaming parachute helps in another way because it aligns the body in a position where the feet enter the water first.’

The website goes on to explain that water is an INCOMPRESSIBLE FLUID. It’s like landing on concrete. Landing in mud, on snow, on trees, on circus tents etc helps break the fall. Moreover, jumping off a bridge into turbulent sea may be safer than jumping into calm water.

On 24th Oct 1930, Vincent Kelly, 31, while working on the Sydney Harbour Bridge fell 170 ft (52 m) into Sydney Harbour and survived.

A champion diver he did several summersaults and landed feet first. He broke a couple of ribs as he did not enter the water at a perfect RIGHT ANGLE but rather a few degrees off perpendicular..

# 2. Water Depth

The next issue is, if you are going to dive or jump into water from a great height and, miraculously, survive the impact, how deep should the water  be?

Olympic divers often practice their dives in a bubble pools (like a spa). This reduces the impact for a bad dive but the water must be much deeper. Sports Smart Canada recommends a water depth of double the height of the drop. But is this realistic if, say, you are jumping or diving from the top of a waterfall into aerated water.

You can work out approximate depths needed if you were jumping into calm water from heights such as below:

How deep do you plunge? The answer is surprising because, in fact, you decelerate really fast in water.

See REd Bull Jump Science here

Thanks to Rod Vance  for the done by hand … not by computer program) for calculating the depth of water when your feet stop moving. That is the minimum depth of water needed for the jump (See graph below)

NOTE: Even with this fancy maths assumptions must be made about the transition epoch-half in/half out of the water.

Assuming you survive the impact and you breath out through your nose – to stop water going up your nostrils really fast- then you will not go any deeper than approx 4 m or 13 ft from a platform of 20 m (65 ft) or less.

If you’re diving into water from, say, a helicopter as in the Demons & Angels movie you don’t need extremely deep water. Assume Langdon was at 100m (328 ft) or the height of The Statue of Liberty(above) or a 33 story building  when he jumped, then extrapolating the graph (above), maybe, a depth of 5m (16 ft) would do.

If you want to see what looking down from a 58.8 m (193 ft) platform looks like check out thisWorld Record Jump by Laso Schaller.

September 16, 2022

It’s Autumn in UK & FALL in the USA so it’s the perfect time for a little bit of outdoor math for Grade 3-5 with AUTUMN leaves. Of course, you don’t need FALL LEAVES for this exercise, but it is colorful.

This fab idea comes from Juliet Robertson, an outdoor education consultant in Scotland. Her blog Creative star learning is one of the most inspiring outdoor maths blogs you will find.

Check out Mathpig’s protractor joke here.

Another fab idea from Juliet Robertson.

## Razzle-Dazzle them with Middle School Math that is, like, WOW!

September 4, 2022

## 10 Quick & Quirky Ways to Make the Math Classroom Rock!

…………………………………………………………..

## 1. Tell a Story: Life, Death, and Geometry

This is middle school maths at its best. To understand Wild Fires you must understand the angle of a slope. REQUIREMENTS: Just this story and a white or blackboard to show how the fire speed changes with the slope angle.

### Background Story

On 5th August 1949 Wag Dodge was dropped by parachute with 14 other firefighters into Mann Gulch, a steep-sided gully in a Montana pine forest. Firefighters who parachute in to put out small blazes started by lightning are called Smoke Jumpers. As they worked their way down the sides of the gully the breeze was blowing away from them. But the wind soon shifted. This produced an updraft, which increases the speed of the fire front. The 15 Smoke Jumpers turned and started running for their lives uphill.

### What you have to know

Heat rises and so there is a Chimney Effect pushing the fire uphill. The rule of thumb used by firefighters is:

Each 10º increase in slope, the fire front speed doubles. So a fire front traveling at 60 kph (37 mph) becomes a fire front traveling at 120kph (75 mph) moving up a slope of 10º.

### What happened to the Smoke Jumpers?

When the fire front changed direction Wag Dodge and 14 other Smoke Jumpers found themselves running for their lives up a steep slope. What did Wag do next?

ANS: Here’s the amazing thing. Wag realised he could not outrun the fire at that point. So he stopped, took off his backpack, took out some MATCHES, and lit a fire in the grassy patch in front of him. Just before the firewall hit he threw himself face down on the burnt patch. He survived. The other 14 firefighters did not. You will find maths exercises here: METRIC UNITS and USA UNITS.

### Requirements: SmartBoard to Project this link.

Try it first. You might be surprised.

## 3. Urban Myth Busted

Requirements: This story.

Goldfish Memory This is what Epidemiologists do. They find out if there are statistics to support the theory. These mathematicians have been providing vital information during the COVID-19 Pandemic.

According to the ABC news, this myth was busted by a 15-year-old Adelaide schoolboy named Rory Stokes. He fed his goldfish near a Red Lego brick. The fish started anticipating food near the brick. He took it away and replaced it several weeks later. The fish remembered the red brick!!! More here.

Other maths myths to check out:

Chewing food 32 times before swallowing helps you lose weight. Here.

You must drink 8 glasses of water a day. Here.

You are 6 degrees of separation from anyone in the world. Here.

It takes 43 muscles to frown and only 17 to smile. Here.

## 4. Beat this! Drum Rates in BPM.

Requirements: A pencil and a timer on a phone.

Can students manage a drumbeat to popular songs? Here are some songs with their BPMs (Beats per minute listed).

Tones and I     Dance Monkey  98 BPM.

The Rubens  Live In Life  104 BPM.

……………….Just Dance          119   BPM

Flume   Rushing Back   176  BPM   (Try the middle of the track. It varies)

Panic! At the Disco      186 BPM   (Recommended by Jog.FM for jogging)

More DRUM BEATS and a story about Drummers’ Brains here.

## ………………………….

Requirements: Phonebook.

Read the instructions at this link. Very simple. And you can amaze the students. Or Vice Versa. A student can amaze a maths teacher.

# 6.  Can you make a Square Bubble?

Requirements: pipe cleaners or stick cube and detergent and a bucket with water.

All ages love this exercise.

# 7. Photo Scavenger Hunt

Challenge: Students use a smartphone to take 5 mathsy photos for homework. Ideas here.

However, start in the maths room. Look for parallel lines, angles, rectangles, spheres, parabolas (not in the textbooks). See parabola below.

# 8. Barcode Maths

Requirements: A product with a barcode.

# 9. Secret Code

Requirements: Box of matches, an accomplice.

## ………………………………………

Requirements: 2 large coins. 20c in Australia, Half-\$ USA or 25p UK.

July 30, 2021

## Toilet Paper FUN FACTS Maths

June 1, 2021

Mathspig is in Melbourne, Australia. We’re in Lockdown. AGAIN!

And toilet paper has disappeared off the supermarket shelves. AGAIN.

So today we are doing maths based entirely on toilet paper using information from the Toilet Paper Fun Facts website. Yes! It exists here.

Toilet Paper Fun Facts Website

Protractor Wind Speed Calculator

POP UP ANS Q 1 & 2 Yr 7&8 Toilet Paper fun facts

Traxxas XO-1 Website

Pythagoras Equation Diagram here

Here is the Sine Rule (Watch 1.5 mins)

Check sine curve here:

Listen to sine curve here:

## Tennis Math: Is player height a BIG advantage? USA units

February 13, 2021

Metric version here.

The Australian Open is on at the moment in Melbourne in LOCKDOWN. (We have 1 community-acquired case. Tennis players are in a bubble.)

# Is height a BIG advantage in tennis?

Here are the heights of 3 top seeds in the Australian  Open. (See graph below)

No. 1 Novak Djokovic    6ft 1″  (73 in)

No. 6 Alexander Zverev  6ft 6’   (78 in)

No. 8 Diego Schwartzman  5ft 7’  (67 in)

# 1. Does serve speed increase with height?

That would be an advantage. Here is a Height vs Serve Speed chart for the Top 6 seeds in the tournament:

Find serve speed data here.

There is NO CLEAR HEIGHT ADVANTAGE for serve speed.

# 2. Does the serve return rate increase with height?

Here is Diego Schwartzman (L) when he defeated Alexander Zverev (R ) in the 2019 US Open.

# What is Schwartzman’s Super Power?

Schwartzman, the shortest player on the circuit (see graph above), tops the service returns stats. Highest 2nd serve return rate. Third highest 1st serve return rate. See data below. So agility, speed, and reaction times are also important factors in becoming a tennis star.

Go Schwartzee! Check data here.

## Tennis Maths: Is player height a BIG advantage? Metric

February 13, 2021

USA units post here.

The Australian Open is on at the moment in Melbourne in LOCKDOWN. (We have 1 community-acquired case. Tennis players are in a bubble.)

# Is height a BIG advantage in tennis?

Here are the heights of 3 top seeds in the Australian  Open. (See graph below)

No. 1 Novak Djokovic  188cm

No. 6 Alexander Zverev  198cm

No. 8 Diego Schwartzman  170cm

# 1. Does serve speed increase with height?

That would be an advantage. Here is a Height vs Serve Speed chart for the Top 6 seeds in the tournament:

Find serve speed data here.

There is NO CLEAR HEIGHT ADVANTAGE for serve speed.

# 2. Does the serve return rate increase with height?

Here is Diego Schwartzman (L) when he defeated Alexander Zverev (R ) in the 2019 US Open.

# What is Schwartzman’s Super Power?

Schwartzman, the shortest player on the circuit (see graph above), tops the service returns stats. Highest 2nd serve return rate. Third highest 1st serve return rate. See data below. So agility, speed, and reaction times are also important factors in becoming a tennis star.

Go Schwartzee! Check data here.

## King Kong Power Punch 2021 USA units

January 30, 2021

Metric version here.

Silverback Gorilla stats here

Human anatomy weight % here.

Speed info here

Impact times for boxers here

Power comparisons here.

## King Kong Power Punch 2021 … Metric

January 30, 2021

USA units version here.

Silverback Gorilla stats here

Human anatomy weight % here.

Speed info here

Impact times for boxers here

Power comparisons here.