A computer simulation is used to demonstrate how the speed of a river varies based on the width and depth of the river channel. A scientist is going to collect data using the computer simulation. They change the width of the pipe and measure the speed of the water. The rate of the water entering the pipe is kept at 1 gallon per minute. What is the independent variable in the simulation? (1 Point) pipe width one gallon per minute water speed depth of the river channel