Projectile Motion of broad jumper

AI Thread Summary
The discussion focuses on calculating the horizontal velocity and displacement of a broad jumper who takes off at a 22-degree angle and reaches a height of 70 cm. The calculated horizontal velocity is 9.16 m/s, and the jumper's vertical motion is analyzed using trigonometric functions and kinematic equations. There is some confusion regarding the definition of "horizontal displacement," with participants debating whether it refers to the distance at the highest point or where the jumper lands. The time to reach the peak height is calculated as 2.3 seconds, but there is uncertainty about how to proceed from this point to find the total horizontal displacement. Clarification on these concepts is necessary for accurate problem-solving.
SigFig
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Homework Statement


A broad jumper begins his jump at an angle of 22 degrees from the horizontal. At the middle of the jump he reaches a height of 70.0cm
a. What is his horizontal velocity
b. What is his horizontal displacement
ANSWER: 9.16m/s

Homework Equations


dh=vht
dv=1/2at^2
t=vv/a

The Attempt at a Solution


Sin 22 = x/70 x= 26.2
26.2=1/2(9.8)t^2
√t
t= 2.3sec

Since it's half way up, you'd have to double the time to find the entire time(?) needed for the entire horizontal displacement, but I have no clue what to do after getting time (if that's even right).
 
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SigFig said:

Homework Statement


A broad jumper begins his jump at an angle of 22 degrees from the horizontal. At the middle of the jump he reaches a height of 70.0cm
a. What is his horizontal velocity
b. What is his horizontal displacement
ANSWER: 9.16m/s


Homework Equations


dh=vht
dv=1/2at^2
t=vv/a

The Attempt at a Solution


Sin 22 = x/70 x= 26.2
No, the angle is his initial trajectory. It does not provide a straight line to his highest point.
What vertical component of speed would he need at take-off to reach that height?
What, therefore, was his horizontal speed?
Btw, it's not clear to me whether "horizontal displacement" refers to where he lands or at the highest point. I think it's the highest point.
 
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