Athlete Long-Jump Question, Don't Know Where I've Gone Wrong

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Homework Help Overview

The problem involves calculating the takeoff speed of an athlete executing a long jump, where the athlete leaves the ground at a 35° angle and travels a distance of 5.80 m. The context is rooted in kinematics and projectile motion.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the need to find the vertical component of velocity using trigonometry and the application of kinematic equations (suvat) to determine the time of flight. There is also mention of the importance of distinguishing between horizontal and vertical components of motion. Some participants question the original poster's use of angular velocity in this context.

Discussion Status

The discussion is ongoing, with participants providing guidance on how to approach the problem by focusing on the components of motion. There is an exploration of different formulas, including the range of a projectile, but no consensus has been reached on a specific method or solution.

Contextual Notes

Participants note that the angle of takeoff and the distance traveled are critical to solving the problem, and there is an emphasis on understanding the forces acting on the athlete during the jump. The original poster expresses confusion about the correct approach and formulas to use.

lando45
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An athlete executing a long jump leaves the ground at a 35° angle and travels 5.80 m. What was her takeoff speed?

I was set this question and have spent about an hour trying to solve it but just can't come up with the correct answer. I found this formula:

Angular Velocity w = 2Π / T
35 = (2 x 3.14) / T
T = 0.179
V = D / T
V = 5.80 / 0.179
V = 32.4


But this is wrong...is there another formula I should be using?
 
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You need to find the vertical componant of the velocity, by using trigonometry.
Then you use suvat to find the time when distance is zero again (i.e. when the athlete hits the ground).

Now you know the time when he hits the ground, and using trigonometry, you can find the horizontal componant of the velocity. Then find how far they have traveled at the time when they hit the ground again
 
lando45 said:
An athlete executing a long jump leaves the ground at a 35° angle and travels 5.80 m. What was her takeoff speed?
I was set this question and have spent about an hour trying to solve it but just can't come up with the correct answer. I found this formula:
Angular Velocity w = 2Π / T
35 = (2 x 3.14) / T
T = 0.179
V = D / T
V = 5.80 / 0.179
V = 32.4

But this is wrong...is there another formula I should be using?

In the question, it is given that the angle at which the athlete leaves the ground is 35°.
This is entirely different from angular velocity.
Also, don't try to solve problems by blindly applying formulas.

For example, in this question, what happens to the athlete during the jump and why? Can you find what forces are acting on him during the jump along the horizontal and vertical directions?
 
Remember that the time in the air only has to do with the vertical componant, and the distance only has to do with the horizontal one.
 
Remember the formula for the range of a projectile. thus you will get the horizontalcomponent as well as the takeoff velocity since the angle the initial velocity vector makes with the surface is already given.
R = v^2sin(2theta)/g
 

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