$\"\"$

The velocity function is $\"\"$ .

The velocity function is varying with time.

Calculus concept is applied here.

Velocity is the rate of change in distance $\"\"$ .

Multiply each side by $\"\"$ .

$\"\"$

Integrate on each sides.

$\"\"$

The distance function is $\"\"$ .

Calculate the distance traveled in $\"\"$ seconds.

Substitute $\"\"$ in the above expression.

$\"\"$

The distance traveled in 15 seconds is 301.81 ft.