Answer:
It cancels recoil.
Explanation:
For each action there is an equal an opposite reaction.
The principle of conservation of momentum tell us that if a single spore were ejected the fern would suffer a recoil from it. This recoil would take energy and speed from the spore. But if they are ejected in pairs the recoil is canceled and all the energy is transferred to the spores resulting in higher speeds.
<span>At the center of the sun, fusion converts hydrogen into helium, neutrinos and another thing that I forgot =/</span>
As we use the Kinetic energy and the equation is 1/2mv^2, changing its mass will change its speed and its energy. So more mass, more speed more energy. also the gravitational potential energy; mass x gravity x height; more mass and more height more speed as it go down to the slope! Hope it helps!