For each half reaction:
>Balance all except O and H
>Balance O using H2O
>balance H using H+
>balance charge using e-
Then multiply the half reactions to balance the e-
Add them back together
Answer: The ball (option A)
Explanation: change in momentum is defined by the formulae m(v - u) where m = mass of object, v = final velocity and u = initial velocity.
For the ball, it hits the ground and bounces back with the same speed, that's final velocity equals initials (v = - u)
Change in momentum = m( -u- u) = m(-2u) = m(-2u) = -2mu
For the clay, it final velocity is zero since it sticks to the floor, hence (v =0)
m(v - u) = m(0 - u) = - mu.
-2mu (change in momentum from the ball) is greater than - mu ( change in momentum of clay)
Answer:
a) 1111.0 seconds
b) 833.3 s
c) Because of proportions
Explanation:
a) Total time of round trip is the sum of time upriver and time downriver

Time upriver is calculated with the net speed of student and 0.500 km:

(Becareful with units 0.5 km= 500m) Similarly of downriver:

So the sum is:

b) Still water does not affect student speed, so total time would be simply:

c) For the upriver trip, student moved half the distance in half speed of the calculation in b), so it kept the same ratio and therefore, same time. So the aditional time is actually the downriver.
Tidal energy is the form of energy used to generate electrical energy.