Hi there!
We can use the following (derived) equation to solve for the final velocity given height:
vf = √2gh
We can rearrange to solve for height:
vf² = 2gh
vf²/2g = h
Plug in the given values (g = 9.81 m/s²)
(13)²/2(9.81) = 8.614 m
We can calculate time using the equation:
vf = vi + at, where:
vi = initial velocity (since dropped from rest, = 0 m/s)
a = acceleration (in this instance, due to gravity)
Plug in values:
13 = at
13/a = t
13/9.81 = 1.325 sec
decomposing water does not require High activation energy
B- we would need the time to fulfill the formula distance = speed x time
S: 198 m
v=39 m/s
u=0
t=?
a=?
v²=u²+2as
(39)²=(0)²+2(a)(198)
1521=396a
1521/396=a
3.84 m/s^2 = a
Hope I helped :)