the acceleration of gravity at the surface of mars is -3.7 m/s squared.a stone thrown upward on mars reaches

Question

reaches a maximum height of 15m.find its initial velocity.what is the total time of flight in reaching that height?time in reaching back the ground?

Answer 1

Using energy formula,
0.5mVf^2=0.5mVi^2-mgh
Since Vf=0,
0=0.5mVi^2-mgh
and, Vi=sqrt(2*g*h)
Vi=sqrt(2*3.7*15)=10.53m/s
Vf= Vi+gt
0= 10.53-3.7t
t= 2.85 s= upward time
backward time=upward time=2.85 seconds

Answer 2

10.53 m/s

Using the formula u^2 = v^2+2*a*s, here final velocity v = 0

Answer 3

5.69 s total time, 10.55 m/s initial velocity