# physics(help me with the angle)

posted by .

In the 1968 Olympic Games, University of Oregon jumper Dick Fosbury
introduced a new technique of high jumping called the "Fosbury flop."
It contributed to raising the world record by about 30 cm and is
presently used by nearly every world-class jumper. In this technique,
the jumper goes over the bar face up while arching his back as much as
possible, as shown below. This action places his center of mass outside
his body, below his back. As his body goes over the bar, his center of
mass passes below the bar. Because a given energy input implies a
certain elevation for his center of mass, the action of arching his
back means his body is higher than if his back were straight. As a
model, consider the jumper as a thin, uniform rod of length L.
When the rod is straight, its center of mass is at its center. Now bend
the rod in a circular arc so that it subtends an angle of θ = 81.5°
at the center of the arc, as shown in Figure (b) below. In this
configuration, how far outside the rod is the center of mass? Report

when i do integration, do i use from angle 49.25 to 122.25

• physics(help me with the angle) -

You are integrating some distance*dm in order to get a cm (mass*distance). There are hard ways, and easy ways to do do this. By arguments of symettry, you can place the cm on the axis, so the question is where.

consider some dm=k dtheta

but the x part of that, the distance along the final radial, is r-rcosTheta

(draw a diagram to verify that).
So just integrating the arc (-81.5/2 to 81.5/2 deg) will give the position.

Int (r-rcosTheta)dTheta= rTheta+rsintheta over limits, or

-r*.71+r(.989)-r(.71)+r(.989)=.558r, or outside the arc, it is .442r.

now in terms of L, L=rTheta=r(1.42) or
r= L/1.42 so

distance is .442*1.42=.62 L

## Similar Questions

1. ### mathematics on sports

can anyone provide me with some sources which has information on how mathematics has been used on sports?
2. ### physics(I'm taking a different way to solve)

In the 1968 Olympic Games, University of Oregon jumper Dick Fosbury introduced a new technique of high jumping called the "Fosbury flop." It contributed to raising the world record by about 30 cm and is presently used by nearly every …
3. ### Physics

An Olympic long jumper is capable of jumping 8.3 m. Assume that his horizontal speed is 9.5 m/s as he leaves the ground. He was in the air for .87 seconds. How high does he go assuming that he lands upright, the same way he was when …
4. ### physics

an olympic long jumper i capable of jumping 8.0 m. Assuming hi horizonal speed is 9.1 m/s as he leaves the ground, how long is he in the air and how high doe he go?

the story name is the fosbury flop by rich wallace basedon the passage readers can conclude that compared to other styles of jumping ,the fosbury flop?
6. ### physics

An Olympic long jumper leaves the ground at an angle of 18.7 ° and travels through the air for a horizontal distance of 7.04 m before landing. What is the takeoff speed of the jumper?
7. ### Physics-HELP

An Olympic long jumper is capable of jumping 7.5 m. Assume that his horizontal speed is 8.8 m/s as he leaves the ground. How long is he in the air?
8. ### Spanish

What is the main difference between the Pan American Games and the Olympic Games?
9. ### math nid this asap tyy

(Velocity and acceleration.) The acceleration of gravity on the surface of the Moon is a = 1.6 m/s2, as opposed to g = 9.8 m/s2 on Earth. An Olympic high-jumper can jump to about 2.35 m on the surface of the Earth. What height could …
10. ### Physics

An Olympic long jumper is capable of jumping 8.44m. Assuming his horizontal speed is 5.644m/s as he leaves the ground, how high does he go?

More Similar Questions