Question

A submarine is at a depth of 100 feet below sea level. Then it starts to dive at a rate of 50 feet per minute. For this situation, what is the independent variable (include units)?

Answer 1

the independent variable is time (t). It's unit is minutes

Explanation:

The initial location = 100 feet below sea level

if sea level = 0 feet

100 feet below sea level = 0 - 100 = -100feet

The rate it dives = 50 feet per minute

Let the position of the submarine after diving = y

let the number of minutes it dived = t

The equation for this: initial location + (rate it dives × time taken in minutes)

y = -100 feet + 50 × t

y = -100 + 50t

y = 50t - 100

Using equation of line: y = mx + c

y = dependent variable, while x = independent variable

Comparing both equations:

y = dependent variable, while t = independent variable

In the absense of options and for the above situation and the workings derived,

the independent variable is time (t). It's unit is minutes