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A person tosses a 150g baseball straight up from an initial height of 2m. THe ball...

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andrewmezzo | Student, College Freshman | Valedictorian

Posted December 9, 2012 at 9:41 PM via web

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A person tosses a 150g baseball straight up from an initial height of 2m. THe ball strikes floor at speed of 7.5m/s. What is inital speed of the ball?

ignore air resistance

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jeew-m | College Teacher | (Level 1) Educator Emeritus

Posted December 10, 2012 at 6:38 AM (Answer #1)

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Using the equations of motion;

`darr V^2 = U^2+2*a*S `

`V = 7.5` `m/s`

`U = ?`

`a = g = 10` `m/s^2`

`S = 2m`

 

`U = sqrt(V^2-2*a*S)`

`U = sqrt(7.5^2-2*9.81*2)`

`U = 4.124m/s`

 

So the initial speed of the ball is 4.124m/s

 

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