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April 18, 2014

April 18, 2014

Posted by **Bart** on Wednesday, November 23, 2011 at 6:52am.

A long jumper leaves the ground at 45 degrees above the horizontal and lands 8 meters away.

What is his "takeoff" speed?

A long jumper is out on a hike and comes to the left bank of a river. There is no bridge and the right bank is 10 meters away horizontally, and 2.5 meters vertically below. If he jumps from the edge of the left bank at a 45 degree angle with the speed calculated in question.

How long or short from the opposite bank will he land?

- physics -
**drwls**, Wednesday, November 23, 2011 at 7:18am#2: 8.0 m = (Vo^2/g)sin(2A) = Vo^2/g

Solve for Vo

For #1, Vx = Voy = 27/sqrt2 = 19.1 m/s

Y = 1 + Voy*t -(g/2)t^2 = 13

Solve for t. Then, use

X = Vx*t for the horizontal distance

For #3, use what you have learned and try it yourself. I assume you are supposed to use the takeoff speed calculated in the previous question.

- physics -
**Bart**, Friday, December 2, 2011 at 7:43pmFor #2 What formula did you use when writing: (Vo^g)sin (2A)? Where did the 2 in the 2A come from?

For #1 Where did the 27/sqrt2 come from?

For #3 I still need help doing this one. I am not yet at the point where I can do it myself.

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