# Equation that is y=(Vi^2)/2g

So if I have a kangaroo on planet Y with a specified gravity of 12m/s^2. If he jumps with an inital velocity of 8m/s, how far would he travel?

Hootenanny
Staff Emeritus
Gold Member
What have you attempted thus far? What are your thoughts?

Well I thought I would use the formula y=Vi(time)+1/2g(time)^2, but I dont have a time, just initial velocity and gravity.

Hootenanny
Staff Emeritus
Gold Member
Well I thought I would use the formula y=Vi(time)+1/2g(time)^2, but I dont have a time, just initial velocity and gravity.
Which other kinematic equations do you know? You need to pick one with all the variables in that you know plus the one which you want to find out.

Well, I also had read about an equation that is y=(Vi^2)/2g but I wasnt sure wether this was a valid equation or a kinematic equation. Any clue?

Hootenanny
Staff Emeritus
Gold Member
Well, I also had read about an equation that is y=(Vi^2)/2g but I wasnt sure wether this was a valid equation or a kinematic equation. Any clue?
Sounds goot to me assume a level ground with no atmospheric resistance.

time of flight for the first half (rising) is t = (v-u)/g = 0.666 sec, sot he time of flight for the last half descent is also 0.666 sec. Total time is thus 1.333 sec.

with no reistance to motion in the x axis the distance travelled is just the (X component of velocity) x time, do you know the angle?