C++

I am attempting an assignment in C++. This assignment requires me to calculate the trajectory of a potato that has been shot out of a potato gun. User inputs the angle and initial velocity, and then the program calculates each step of the balls trajectory on the x and y axis every second.

These values will then be passed into a 2D array, which will output to an excel file.

I have the maths down. And I know to convert to radians after the angle has been input. I am having problems passing the values into the 2d array. Arrays in general are just super confusing for me.. I know a for loop is needed, but I can't get the data to insert into the array.

Could I get a sample program that does the basics of what I need here, so I can see how each second is passed into the array?