BMX

INTRO TO BMX - What is BMX Racing? Why did it begin? https://m.youtube.com/watch?v=qMXlH64prJw (13-1:00)

WHO? CONNOR FIELDS

• Olympic Gold Medalist, Rio de Janeiro, Brazil 2016
• 6’, 195lb, competes professionally in the Olympics for team USA
• Does national championships as well
• Started at age 8

WHO? MARIANA PAJON

• Olympic Gold Medalist London Olympic Games 2012
• 5’2”, 135lbs, competes in the Olympics for team Columbia
• In London she won the first Gold Medal for her her country in that event, as well as the second EVER for her country since its participation in the Olympics began in 1932

PHYSICS AND BMX

THE BIKE

Starting Gate
- Torque τ=Iα, α=ω/t, I=m(r^2), ω=v/r
- Gravity 9.8m/(s^2)
Dimensions:
(L1/H)=8, (L2/W)=18.3, H=20

RHYTHM SECTION

• Conservation of Momentum (is the goal at least. (m1)(v1)=(m1)(v2), v1=v2
• Manipulation of center of mass
• Maximizing flow and timing
• Pumping; adding work, and work=E, the E increases v

JUMPS

• Conservation of momentum
• Manipulation of center of mass to maintain a parabolic shape of motion

BERMS

• Slingshot effect-decreasing radius of the curve
• Force Normal isn’t perpendicular to the ground & assists motion in the x direction

SAMPLE PROBLEM

• Find the speed of the BMX at the end of the hill if it’s just rolling.
• Find the power exerted by the rider to go the average exit speed at the bottom of the ramp. (35mph-15.6m/s)
• Extra Credit: If Connor’s final velocity is 19 mps, how much power is he adding to the bike?