4. You are standing on the surface of the an unknown planet with no at- mosphere. In order to test the acceleration due to gravity, you throw a ball at a speed of 10 m/s at an angle of 25 above the horizontal from a height of 1 meter. You measure the time it takes for the ball to hit the ground to be 4.45 seconds. a) What is the acceleration due to gravity of this unknown planet? b) What is the impact velocity of the ball when it hits the ground? c) How far away from you will the ball land?