Physics A123 Acceleration problem

AI Thread Summary
To determine the speed needed for a person to jump to a height of 130 cm, the relevant physics equation is v^2 - u^2 = 2as, where v is the final velocity, u is the initial velocity, a is the acceleration due to gravity, and s is the height. The final velocity at the peak of the jump is zero, allowing for the calculation of the initial velocity required to reach that height. The discussion highlights the challenge of using equations with multiple unknowns and suggests focusing on equations with a single unknown for clarity. The participant expresses difficulty in grasping physics concepts, emphasizing the complexity of the subject. Understanding the relationship between height, velocity, and acceleration is crucial for solving the problem effectively.
c_barrera2
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Homework Statement

Excellant human jumpers can leap strait up to a height of 130cm off the ground. To reach this height, with what speed would a person need to leave the ground?



Homework Equations


I would just like to know what equation I would need to solve this,


The Attempt at a Solution


xf = xi +(vx) (delta)t + 1/2ax(deltat)^2
 
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Since the equation you list has 2 unknowns , vx and t (a is known), you can't solve it without another equation. Why not instead try another equation that has just one unknown, vx (the initial velocity)? You must first note what is the the final velocity at the top of the jump, and what is the acceleration?
 
you can use this eqn

v^2 - u^2 = 2as
 
Last edited:
hmmmm, yeah this is all the iformation its giving me, I'm trying to find the (Vx)f, the final velocity of this person. if I'm not mistaken this equation would look like a parabola, right?
 
ya see I'm a first time physics student you know...and generally I can teach myself a a subject, haha but physics it not just any other subject...its like the king of all science subjects
 
why 2 unknowns?
my eqn gives you the answer ... can't write the answer ... got warnings for writing answers ...

what do you think v(final) would be?
 
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