## Posts Tagged ‘calculate’

## Death by Chocolate for CATS

February 21, 2021#### Chocolate contains a poison called Theobromine.

#### LD50 for Theobromine for cats is 200mg.

#### LD = Lethal Dose. LD50= Lethal Dose for 50% of the population. Cats in this case. This is how poison toxicity is measured.

#### According to The Royal Society of Chemistry, cats are hypersensitive to Theobromine but, as cats cannot taste sweetness, they are rarely poisoned.

## Real World Maths: %, vaccines and saving humanity

November 29, 2020**The following information comes from the article 2 Companies Say Their Vaccines Are 95% Effective. What Does That Mean? Carl Zimmer, New York Times, 20 Nov 2020.**

**See Principles of Epidemiology here.**

As Dolly Parton donated $1Million to Moderna, the vaccine research group, it is only appropriate to include a VACCINE parody of her hit song, Jolene put together by the Dept of Health, AUSTRALIA.

## Real World Maths: Gotye and Some $$ that he got to know

November 12, 2020**Melbourne singer, songwriter, and geometrically inclined performer Gotye performing with Kimbra won 3 Grammy Awards for his song Somebody that I used to Know in 2013.**

**The Gotye youtube clip has had 1,535,344,012 or 1.5 Billion hits since it was first uploaded 5th July 2011. **

## Mini Rates Exercise:

**In 111 months Somebody that I used to know has scored 1.5 Billion hits. How many hits a. per month, b. per day, c. per minute? (Round off numbers)**

**Ans: a. 13.5 Million per month**

** b. 450,000 per day (Assuming 30 days per month)**

** c. 37,500 per hour and 625 per minute (for over 9 years non stop!)**

**Estimate of Youtube Earnings for this Song:**

**The Influencer Marketing Hub **puts the rates an advertiser pays between **$0.10** to **$0.30** per view on Youtube, but averages out at $0.18 per view. Using the lower rate, how much has this song earnt in just over 7 years?

**Earnings = 0.10 x 1.5 x 10 ^{9 } = 1.5 x 10^{8} = $150,000,000 = $150 million***

*This calculation is based on a click per view of the video. Gotye will not receive anything like $150M, however, because advertisers pay per click on their ad.

**According to the Influencer Marketing Hub again ‘on average, the YouTube channel can receive $18 per 1,000 ad views. This equates to $3 – $5 per 1000 video views.’ Again, using the lower rate:**

**Video Hits =1.5 x 10 ^{9}**

**Divide by 1,000 = 1.5 x 10 ^{9 }÷10^{3} = 1.5 x 10^{6}**

**$3.00 per 1,000 video clicks earnings = 3.00 x 1.5 x 10 ^{6} = 4.5 x 10^{6}**

**Realistic Earnings = 4.5 x 10 ^{6} = $4,500,000 = $4.5 million**

**A Geometric Parody:**

**Here is Mathspig’s take on the song:**

**Somebody that I used to Know:**

**It’ll either help students do their exercises or work like Clockwork Orange and have them running screaming out of the room when they hear the first few notes.**

## Real World Maths: Fractions & Guitar Sizes

September 11, 2020## Crazy Math: How to survive a Wagon Wheel Rolling over your head

March 26, 2020There is some amazing Middle School Maths in The Cake Server on Joseph’s Machines.

eg. Calculate the length of the arc of a circle to fit your HEAD! Watch for it.

Besides, this is so much FUN!

## 1. Stuntman Math: Car Stunts

October 20, 2019#### “With enough stupidity you can get any car to roll over” (MSN AUTO)

# What stuntmen and women need is maths!

Maths is essential to the process, from calculating speeds and braking distances to looking at the ratio of the amount of film shot to the length of time of the end sequence. The stunt and crash is outlined, and the co-ordinator explains how he must calculate speeds and stopping distances carefully.

**So you want to be a stuntman?**

First think of the pain.

Mark Eiden, 52, a professional stuntman (pictured) who is not only afraid of heights, but was once told he likely wouldn’t walk again. Eiden’s had surgery on both arms and shoulders, five knee surgeries, six nasal reconstructions, foot and hand surgery and a facial cast. He fell off the top of a stunt car at 40 mph when the tyre blew. He gaffer taped his ear and continued, despite severe concussion. Northern Express Michigan

If you still want to be a stuntman do the Maths:

# Rolling a Car:

You can use quick handbrake turn, speed around a corner, fishtail into the curb or some other lunatic thing. The most controlled way to roll a car is to use a ramp.

These ramps often have a kicker at the end to add extra lift. Ramp calculations can be complicated, but the simplest way to look at the maths is to determine the angle a car will roll ie. When the Centre of Gravity moves over the base.

# Centre of Gravity vs Base Width

The distance between the front wheels in cars is often called the track width.

Table from Accident Reconstruction Website

So the Lamobgini Diablo is very hard to roll (build a higher ramp) and it therefore beats the SUV for stability every time.

# Balancing on 2 Wheels

A more skilled stunt involves driving a car on two wheels. A very skilled stunt driver can lift the car onto wheels by snaking the car back and forth across the road until it balances on 2 wheels.

From the Centre of Gravity vs Base angles above you can see that the SUV is the easiest car to balance of 2 wheels.

But there is nothing quite as crazy as this SUV stunt:

# Saudis changing car tyres, just insane.

View full video here.

Safe Driving Info here

## 3. STUNTMAN MATH: Motorbike Jump

October 9, 2019### This is a repost of Mathspig’s very popular Stuntman/woman series.

# Star Stuntmen

Star Stuntmen Monte Perin (pictured) has involved many films, including “Spider-Man,” “Star Trek, “Indiana Jones and the Kingdom of the Crystal Skull” and portraying Arnold Schwarzenegger’s stunt double in “Terminator 3: Rise of the Machines.”

Perhaps his most difficult stunt was landing his Harley in an open boxcar of a moving train for Disney’s 2008 Adam Sandler movie “Bedtime Stories”. In a career of over 25 years Perin has broken “almost everything” including both his arms, legs, knees, feet, ankles, several ribs, his back and his pelvis. See Confessions of a stuntman

Veteran stuntman Evel Knievel (1938 – 2007) was the pioneer of many stunt jumps. Here he is jumping 10 cars and 3 vans in 1973.

His injuries are legendary:

More Evel Knievel

# Ramp Design

The angle of the kicker in ramp design can vary from 10^{0} – 70^{0} (See below)

# Moto-X Ramp Jump Maths

As any bike nut knows increasing speed and angle of take off will increase jump distance.

Here is a graph from final gear for speed vs angle to jump 90m.

METHOD 1 is approximate (See STEP 1 & STEP 2 above), but as METHOD 2 produces the same ans (See above), it is very useful.

You will find a thoroughly detailed calc for STUNT JUMP MATHS here:

And everything you ever wanted to know about PHYSICS OF STUNT JUMPS here.

## 4. If you are involved in a car chase, hijacking, explosion, volcanic eruption or alien invasion, you will not go into shock.

January 10, 2019Here are just a few of the popular disaster movies:

**Avalanche **(2001),** Earthquake **(1974)**, Armageddon **(Involves meteors 1998),** Deep Impact **(More meteors 1998),** 2012 **(Tsunamis, earthquakes, the lot. 2009)**, Twister **(tornadoes 1996), **Backdraft **(Fire. 1991) and** Towering Inferno** (They don’t make thunderous movie titles like that anymore. (1974)

But what percentage of people involved in, say, an explosion suffer from SHOCK! There are many statistics about Post Traumatic Stress Disorder (PTSD) available. In **one excellent study** in The National Centre for PTSD Journal involved an explosion in a paint factory in Norway (1976), the 246 employees were ranked for their exposure to shock as follows:.

A. 66 Narrow escape

B. 59 Involved but not in danger

C. 121 Not present on the day.

80% Group A suffered shock and PTSD. Both Groups A & B showed symptoms of PTSD 7 months later. If, say, a plane crashed into your school sports field and your class survived with minor injuries calculate how many students in your maths class would go into SHOCK and how many would be left to take action using the above statistics.

These stats can also be used as a fraction or decimal exercise using 0.8 or 4/5 as the fraction of students in shock.

More information at the** Health Dept WA**

NOTE: Many schools in Australia today not only practise fire drills but terrorist attack lockdowns.

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

January 10, 2019 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.