Sunday, November 3, 2013

2008 world record for highest mototrcross jump

Redbull's no limits competition had Robbie Maddison jumping his motorcycle to the top of a 96 ft tall building. Check out the video here:
Here's a write up of the event - comparing it to the previous years' distance record:
Having broken the Guinness World Record for a motorcycle with a leap of 322
feet, 7.5 inches over the length of a football field during the 2007 Red
Bull New Year’s Eve event, Maddison had nowhere to go but up – more than
100 feet up. In front of a crowd of more than 300,000 New Year’s Eve
revelers chanting his name, the 27-year-old Aussie accelerated to 55 miles
per hour and launched his bike 105 feet high, landing on the top of the
96-foot-high and 40-foot-deep replica Arc de Triomphe in front of Paris Las
Vegas. After successfully landing on the top, Maddison swung his motorcycle
around and dropped a dizzying 60-plus feet to a landing ramp below, the
immense force of the impact lacerating his left hand, which was sutured at
a local hospital. Maddison’s impressive resume, in addition to his
record-breaking distance jumps, includes a very successful freestyle
motocross career.
“I just cheated death again,” said Maddison. “I’m ready to live another day
and am extremely excited to see what 2009 holds for me. The risk level of
my jumps was extremely high, and although I was confident in my abilities
and preparation, I knew there could have been major consequences, but that
is what pushing the limits is all about.”

So, if he was going 55 mph, what is the maximum height he could have reached? (Remember to use a conversion)

Why did he not reach that height?
How much of his energy was lost in reaching his maximum height?
Assuming the same ratio of energy loss, how fast would he be going when he hit the ramping the way down, 60feet below the top of the building?

Saturday, November 2, 2013

Which law is it?

I am always amazed by how often I see newtons laws in action. Watch this video:
  • Which law is being shown here? (Actually, you can see all three, but there is one that is more obvious that the others)
  • See if you can identify at least 2 examples of each of newtons laws in this video!


Also, we can talk about torque here. 
  • A large flatbed truck like this can have a mass of 3,000 kg mass. If the center of mass of the truck is 4 m in front of the axle, and the rear of the truck is 2.5 meters behind the truck, how much weight could you have centered over the back edge before tipping the truck up?
  • When balanced like in #2, there are only 2 significant torques. What force provides the 3rd force to keep the system from rotating when the load is not that heavy?
  • Can you draw a torque diagram for this when the truck is tilting up from the weight of the load?