Respuesta :

     a)
Acceleration of stone = 10

Integrate:
So velocity = 10t

Integrate again:
So distance from starting point = 5t^2

Distance from ground = 450-5t^2

b)
450 - 5t^2 = 0


9.48 seconds

c) velocity = 10t

Put the time into this to give:

94.8 m/s

d.

Velocity = 10t + 5

Integrate again:

5t^2 + 5t


Solve
5t^2 + 5t = 450

Gives 9 seconds
When the stone hits the ground, h= -4.9 t^2 +450=0> 450=4.9t^2> t^2= 450/4.9 > t=
sqrt/ 450/4.9 = 9.583 seconds

V= -9.8 When it hits the ground,t=9.583 and v= -9.8(9.583)=
-93.91 m/sec

If the stone is thrown downward with a speed of 5 m/sec, how long does it take to reach the ground? t= 55+_sqrt/ 5^2-4(4.9)(-450)/2(4.9) =9.087 and -10.107
9.087 sec