Force is defined as the rate of change of momentum.
The initial amount of momentum is

because water stops when it hit the wall total change of momentum must be

.
Now let's calculate the force.

We need to find

. This is the amount of water hiting the wall per second.

Our final formula would be:

And now we can calculate the answer:
Answer: B. 15.2s
Explanation: 600/39.5 = about 15.2
Dalton's atomic<span> theory proposed that all matter was composed of </span>atoms<span>, indivisible and indestructible building blocks. While all </span>atoms<span> of an element were identical, different elements had </span>atoms<span> of differing size and mass</span>
Potential energy and kinetic energy
As change is velocity is
<span>Δv=<span>10 m s<span>−1</span></span>−<span>2 m s<span>−1</span></span>=<span>8 m s<span>−1</span></span></span>
and time taken is 3 seconds so acceleration is
<span>acceleration=<span>change in velocitychange in time</span></span>
So
<span>a=<span><span>8 m s<span>−1</span></span>3 s</span>=<span>2.7 m s<span>−<span>2</span></span></span></span>