Answers

2014-08-28T17:41:21+05:30
Use the formula s=ut +1/2g(t*t) and g=(v-u)/t
where s= 20 m
g=9.8m/s
u=0m/s
t=2s/g whole under root
1 5 1
  • Brainly User
2014-08-28T17:41:29+05:30
H=20m/s
u=0
v=?
t=?
v²-u²=2gh
v²-o²=2*10m/s * 20m
v=√400
v=20m/s[velocity with which stone hit the ground]
v=u+gt
20=0+10*t
t=2s[time to reach the ground] 
1 5 1
h=20m,u=0m/s v=? a=10m/s2 speed=? using the equn v2= u2+2as v2=0+2x20x20 v=sgureroot of2x400=40m/s v=u+at t=v-u/a 40-0/10=4s then speed=velocity/time=40/4=10m/s