Using Kinematic Equation w/ Constant Velocity: Solving Time of Fall

[celect]

How do I use Kinematic equation with constant velocity.
I only have used with intital and final velocity.



A parachute dropped from a 30-meter-high cliff falls with a constant
velocity of 1.5 meters per second. Twenty-two seconds later a stone is
dropped from the cliff.

a. How long does it take the parachute to hit the ground?


b. How long does it take the stone to hit the ground?
I solved this using d=v_i * t + 1/2 * a *t ^2

24.5 seconds

 

[Doc Al]

Originally posted by celect
How do I use Kinematic equation with constant velocity.
I only have used with intital and final velocity.

You can use the exact same equation by setting a=0. It simplifies to d = v*t ... I hope that equation looks familiar!

 

[celect]

d=v*t+1/2*a*t^2

-30m = (-1.5m/s)*t + 0.5 (0m/s)*t^2

I come up with t=20s

Am I going in the right direction?

 

[himanshu121]

yes, if the velocity remains contant
then a=0

 

[Doc Al]

Originally posted by celect
Am I going in the right direction?

Perfect.