Aquila Children's Magazine AQUILA Magazine Best Bits | Page 36

Not the first venue that springs to mind
Skateparks. A place to hang out with your friends at the weekends, right?
Kit. The skatepark is where I go to
when you think of maths and science, is it? (Nope, definitely not,
carry on. Ed)
get away from Harvey and Calculata when they send me into overload, but
Did you know that your local skatepark
is actually a great place to put
mathematical theory – think calculus
– into action?
Accurately calculating your motion and
velocity as well as understanding angles,
circles and how to use your body’s
centre of gravity, can make the
difference between pulling off a trick
perfectly, or falling on your…erm… mass.
A NEED FOR SPEED
(AND MOMENTUM)
What’s the best way to pull off a trick? Too
fast and you’ll fly off the end of your
board and smack into a wall. Too slow and
you’ll never build up enough energy to
pull off a stunt or leap across a void.
How can you even tell how fast someone
is travelling?
RAD REVOLUTIONS
SPEED EXPERIMENT
Set up a long tape and stand by with a
stopwatch in your hand. Time how long
it takes your friend to run or ride from
the start of the tape to the end of the
tape. Write down the length of the tape
e.g. 30 metres and the time e.g. 9
seconds. To work out how fast they
travelled, divide the distance by the
time.
When 12-year-old
Tom Schaar
landed the
world’s first
1080 trick
(that’s three
full
rotations in
the air
before landing)
30 metres ÷ 9 seconds = 3.33 m/s.
That’s how fast they were travelling in
metres per second, to convert it to miles
per hour – times the answer by 2.24
(3.33 x 2.24 = 7.5 mph). in 2012, scientists
Your turn – what will you discover about
the speed of your skateboarding
friends? Can they time you? What else
can you observe? children have an advantage over adults
and mathematicians
were baffled. How had Tom been able
to do it? Was his incredible success
down to his size and weight? Do
on performing such feats?
Rhett Allain, an associate professor of
physics, pondered these questions and
figured out that bigger doesn’t always
Momentum is the measure of mass in
motion. Change in mass or velocity
(speed) can change momentum.
The formula is p = mv (p = momentum).
Momentum = mass x velocity.
Imagine you’re travelling on a skateboard
at 20 m/s and you weigh 50 kg. You could
calculate momentum as: 50 kg x 20 m/s =
1000 kg m/s. The momentum the rider
builds up is transferred into the trick they
pull. A successful use of momentum
would be catching air on a ramp. A
momentum fail would be crashing into
the ramp, losing momentum and velocity
and bruising your bottom.
A skateboarder weighs 40 kg and travels
at 20 m per second.
What is their momentum?
800 kg m/s
There is a mathematical formula for
calculating speed.
mean the same. By this, he meant that
you can’t just use scale when
comparing small with large – there are
many variables that need to be taken
into consideration and adjusted. Maybe
if the first person to pull a 1440 is a
6-year-old, then we will be closer to
knowing whether size does matter!
There are 360 degrees in a circle.
There are 180 degrees in a semicircle.