Answer:
Living organisms need water to survive. Many scientists even believe that if any extra-terrestrial exists, water must be present in their environments. All oxygen-dependent organisms need water to aid in the respiration process. Some organisms, such as fish, can only breathe in water. Other organisms require water to break down food molecules or generate energy during the respiration process. Water also helps many organisms regulate metabolism and dissolves compounds going into or out of the body.
Explanation:
Answer:
v = 16.49 m/s
Explanation:
Given that,
Length of the string, l = 1.15 m
The ball makes 137 complete turns each minute.
We know that, 1 turn = 6.28 rad
137 turns = 860.79 rad
1 min = 60 s

We need to find the tangential velocity of the ball. It can be given by

So, the tangential velocity of the ball is 16.49 m/s.
Negative force
The woman is applying force to stop the child or to prevent him from running.
I hope this helps...
Answer : The rate constant at 785.0 K is, 
Explanation :
According to the Arrhenius equation,

or,
![\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7BK_2%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%20R%7D%5B%5Cfrac%7B1%7D%7BT_1%7D-%5Cfrac%7B1%7D%7BT_2%7D%5D)
where,
= rate constant at
= 
= rate constant at
= ?
= activation energy for the reaction = 262 kJ/mole = 262000 J/mole
R = gas constant = 8.314 J/mole.K
= initial temperature = 
= final temperature = 
Now put all the given values in this formula, we get:
![\log (\frac{K_2}{6.1\times 10^{-8}s^{-1}})=\frac{262000J/mole}{2.303\times 8.314J/mole.K}[\frac{1}{600.0K}-\frac{1}{785.0K}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7BK_2%7D%7B6.1%5Ctimes%2010%5E%7B-8%7Ds%5E%7B-1%7D%7D%29%3D%5Cfrac%7B262000J%2Fmole%7D%7B2.303%5Ctimes%208.314J%2Fmole.K%7D%5B%5Cfrac%7B1%7D%7B600.0K%7D-%5Cfrac%7B1%7D%7B785.0K%7D%5D)

Therefore, the rate constant at 785.0 K is, 