!PLEASE HELP! WILL GIVE BRAINLIEST!!

A projectile launched straight up into the air with an initial velocity of 20 meters per second from a height of 10 meters. How long will it take for the projectile to hit the ground?

please solve and show your work!!

Respuesta :

Answer: 7.0s

10=20t-1/2(9.8)t^2 multiply every term by 2 and move all terms to one side

t^2-40t+20=0 solve for t using quadratic formula and double answer for total flight time.

t=3.498*2=7.0s