Newton’s Second Law of Motion describes the relationship of force, mass and acceleration using the mathematical equation f = ma. A stack of ten pennies has a mass of 25 grams and is sitting at rest. How many Newtons of force would have to be applied to get the stack accelerating to 0.25 m/s2? (Include the unit of measurement, Newtons, in your answer)

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.