Question

HELLPPP ASAPPPP!!!!!

Answer 1

Answer:

$initial velocity=19 ms^{-1}$

greatest height=48.05 m

Explanation:

Applying motion equations,

upward motion (g= -10m/s2)

where

u = initial velocity

v = final velocity

g = gravitational acceleration

s = distance

$v^{2}=u^{2} +2gs\\31^{2} = u^{2}+2*(-10)*(-30)\\u^{2}=361\\u=19 ms^{-1}$

2)when the rock is at the highest point the velocity = 0

$v^{2}=u^{2} +2gs\\0=361-2*10*S\\S=18.05 m$

total high to the highest point = 18.05 +30

                                                  = 48.05 m