Help with this 9th grade motion problem

  • Thread starter johsun123
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  • #1
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Help with this 9th grade "motion" problem

Homework Statement



2 stones are thrown vertically upwards with initial velocities U1 & U2. Prove that heights recahed by them is in ration U1squared:U2squared.

Homework Equations



S=u+at u being initial velocity

The Attempt at a Solution



since a and t will cancel out, ration should be u1: u2 not the squared. What am I missing?
 
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Answers and Replies

  • #2
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Use the conservation of energy to find the relationship between the 2 heights.
 
  • #3
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Care to explain it a bit more? Which is the equation you are referring to?

We are yet to learn law of conservation of energy.
 
  • #4
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If you throw a stone up with velocity U1, how high does it get?
 
  • #5
HallsofIvy
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Homework Statement



2 stones are thrown vertically upwards with initial velocities U1 & U2. Prove that heights recahed by them is in ration U1squared:U2squared.

Homework Equations



S=u+at u being initial velocity
This is incorrect. u+ at is the formula for the speed at t seconds given initial velocity u and acceleration t. Do you have a formula for distance or height of an object moving with constant acceleration?

The Attempt at a Solution



since a and t will cancel out, ration should be u1: u2 not the squared. What am I missing?
 

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