The force on an object was kept constant for 1 second and then changed to a new value for each successive second, for a total of five force values over a five-second time interval. All five forces were in the same direction and had magnitudes of 0 newtons, 5 newtons, 15 newtons, 5 newtons, and 0 newtons. What was the magnitude of the total impulse, in newton seconds, exerted on the object during this time?