Answer:
Potential Energy is the energy that is waiting to be released like at the top of the roller coaster, Kinetic energy is the energy that is moving the rollercoaster downhill fast.
Three Laws:
The rollercoaster will rest at the top, and then the gears will make it move downhill, and make it stop.
The gears make the rollercoaster move, and in reaction, it pushes back on the gears.
Answer: Sea otter is the pioneer species in the kelp forest as it regulates and controls the population of other species in the kelp forest.
Explanation:
If sea otters are hunted and their population is brought to extinction then this will cause major harm the ecosystem of the kelp forest and it will disturb the ecological balance in the kelp forest. The herbivorous animals consumed by the sea otters will increase in population and they will consume a lot of vegetation in the forest. The kelp forest which forms the coastline will not remain effective in providing protection against the storms to the neighboring areas.
For the work-energy theorem, the work needed to stop the bus is equal to its variation of kinetic energy:

where
W is the work
Kf is the final kinetic energy of the bus
Ki is the initial kinetic energy of the bus
Since the bus comes at rest, its final kinetic energy is zero:

, so the work done by the brakes to stop the bus is

And the work done is negative, because the force applied by the brake is in the opposite direction to that of the bus motion.