Frisbees are a popular summertime toy, but they involve some pretty neat physics, too. Two key ingredients to their long flight times are their lift generation and spin. A frisbee in flight behaves very much like a wing, generating lift by flying at an angle of attack. This angle of attack and the curvature of the disk rim cause air to accelerate over the top of the leading edge. Airflow over the top of the disk is faster than that across the bottom; thus, pressure is lower over the top of the frisbee and lift is generated. Aerodynamic lift and drag aren’t enough to keep the frisbee aloft long, though. Spin matters, too. If the frisbee is launched without spin, gravity acts on it through its center of mass, but lift and drag act through a point off-center because lift tends to be higher on the front of the disk than the back. This offset between gravitational forces and aerodynamic forces creates a torque that tends to flip the frisbee. By spinning the frisbee, the thrower gives it a high angular momentum acting about its spin axis. Now instead of flipping the disk, the torque caused by the offset forces just tips the angular momentum vector slightly. Physically, this is known as spin stabilization or gyroscopic stability. Tomorrow we’ll take a closer look at airflow over the frisbee. (Image credit: A. Leibel and C. Pugh, source video; recommended papers by: V. Morrison and R. Lorentz)
I sometimes forget that Death is a female (who’s in love with deadpool) in the Marvel universe.
I will always reblog this.
I always get a kick out of their relationship, mostly because it’s oddly normal.
avatar: the last airbender was a very beautiful show
He didn’t like being barricaded in the office on a Saturday
don’t say you’re a writer if you just write fanfiction for your entertainment. you’re only a writer if you kill a bear with a typewriter to appease the spirit of hemingway and slather yourself in ink in tribute to shakespeare, the one true over-penis of literature.
ill never not reblog this
He learns from the best.
[FOUND] Ross (Rubberninja the animator) and Holly (CommanderHolly) rocking their sweet Shovel Knight cosplays at PAX East