Calculated the total time kinematics

  • Thread starter Thread starter jacy
  • Start date Start date
  • Tags Tags
    Kinematics Time
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
2 replies · 3K views
jacy
Messages
76
Reaction score
0
Hi,
Here is the problem that am working on.

A stone is thrown vertically upward with a speed of 12.0 m/s from the edge of a cliff 70 m high.
(a) How much later does it reach the bottom of the cliff?
(b) What is its speed just before hitting
(c) What total distance did it travel.

I have calculated the total time it takes to reach the bottom of the cliff, but haven't been able to do the (b) and (c) part. Here is what i have done

I used this formula to compute the time and am getting it right.

x= x(0) + v(0)t + 1/2 at^2

0= 70+12t+1/2(-9.8)t^2
t= 5.2 seconds, -2.75 seconds

the ans to the c part is 84.7m and b part is38.9 m/s. Please suggest me a hint. Thanks
 
on Phys.org
Looks like you need to find the maximum height the stone makes it to, for B) and C). Remember at the max height velocity = 0
 
And remember that the V0 will be positive in the velocity equation