Energy of water is also a form of solar energy. explain.

Each and every amount of energy on earth is come from the Sun, therefore what ever energy we see around us is eventually come from the Sun.

Water posses energy in two form form, one is at potential energy in which water is flowing at a very high altitude, while other is in the form of chemical energy of the water bond.

Water flows at the higher altitude because sun evaporates the water from the ocean, which later condensed when get opposed by mountains, and flow at higher altitude, while the water is formed due to excessive heating of the earth due to solar radiation and presence of oxygen on the earth, thus both the reason are cause by sun, hence we can say that all the energy of the water is the form of solar radiation

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s

your answer is c! hope this : )