In 2012, James Cameron descended to the bottom of Challenger Deep in the Marianas Trench; the deepest point in the ocean. The vessel he rode in was called DeepSea Challenger. Challenger Deep is 35,814 feet deep at its lowest point

DeepSea Challenger’s descent was a change in depth of (-4) feet per second. We can use the equation y = -4x to model this relationship, where y is the depth and x is the time in seconds that have passed.
How many seconds does this model suggest it would take for DeepSea Challenger to reach the bottom?

y

Bonus points:
A submarine is descending to examine the seafloor 3,100 feet below the surface. It takes the submarine 2 hours to make this descent. Write an equation to represent the relationship between the submarine's elevation and time. (y is the elevation and x is the hour)