Posted by George on .
A long jumper leaves the ground at an angle of 20 degrees and travels a horizontal distanceof 7.0m before landing. What is the takeoff speed of the jumper?
To be honest I really don't know how to solve it. A stepbystep explantion would be helpful.

Physics 
bobpursley,
Horizontal:
7=viCos20*timeinair
timeinair=7/Vicos20
Vertical:
hf=hi+ViSin20*t4.9t^2
put the timeinair expression in for time
0=0+ViSin20(7/cos20)4.9(49/cos^2 20)
compute Vi