Sir Isaac Newton, held the theory that light was made up of tiny particles<span>. In 1678, Dutch physicist, Christiaan Huygens, believed that light was made up of </span>waves<span>vibrating up and down </span>perpendicular<span> to the direction of the light travels, and therefore formulated a way of visualising wave propagation.</span>
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.
Answer:
The mass of Uranium present in a 1.2mg sample is 
Explanation:
The ration between Uranium mass and total sample mass is: 
For a sample of mass 1.2 mg, the amount of uranium is:
Answer:
D
Explanation:
Gene flow is the transfer of genetic variation from one population to another
