You are asked to re an object from the ground straight up into the air such that it remains in the air for a total of 4 seconds before it returns to the earth and hits the ground. lfyou use the estimate that the acceleration due to gravity [g] is equal to 10 m/s2 pointing toward the center of the earth: a. What magnitude of velocity should the object have when it is red in order to remain in the air for 4 seconds? b. If you misunderstood your instructions, and used the same magnitude of velocity as calculated in part a, but red the object at an angle with respect to the vertical direction, would the object spend more, less, or the same time in the air? Be sure to justify your