I NEED HELP I AM SO CONFUSED, WILL GIVE BRAIN. You are standing at the edge of a cliff that is 40m tall. You throw an apple down with a speed of 15 m/s. How long does it take to fall to the bottom of the cliff?

Students in an introductory physics lab are performing an experiment with a parallel-plate capacitor made of two circular aluminum plates, each 11 cm in diameter, separated by 1.0 cm. how much charge can be added to each of the plates before a spark jumps between the two plates? for such flat electrodes, assume that value of 3×106n/c of the field causes a spark.