# How to solve this projectile problem?

1. Oct 8, 2012

### Nubcake

A long jumper projects himself at an angle for take off . His long jump measures 7.5m and he is recorded as being in the air for 0.80 s. He falls through a distance of 0.95m between his take off position (when he is standing) and his landing position (when he is lying down)

a) Calculate his horizontal and vertical velocities at take off
b) Hence calculate the angle at which he projects himself at take off

t=0.8
a=-9.8 (up is positive)

I do not have a solid understanding of the question , has he fulfilled his long jump or not? Did he jump 7.5m total and jumped up to 0.95m before coming back down or did he fall as it says so his displacement is 0.95m and 7.5m is what then?

Tried drawing it out but couldn't make nothing from it.

Last edited by a moderator: Oct 8, 2012
2. Oct 8, 2012

### tiny-tim

Hi Nubcake!
He's just under 2m tall.

His centre of mass is 0.95m off the ground when he's standing (or running), and is 0.00m off the ground when he's lying down.