How many joules of gravitational potential energy are stored in an object that has a mass of 8.5 kilograms and is held 2 meters above the surface of earth?

How do i start to solve? would appreciate a walk-thru! a bird sitting 16ft above the ground in an apple tree dislodges an apple. after how many seconds does the apple land on the ground? (assuming that no branches will interfere with it's fall)

Abag contains 10 white golf balls and 6 striped golf balls. a golfer wants to add 112 golf balls to the bag. he wants the ratio of white to striped gold balls to remain the same. how many of each should he add?

Y= 4x + 3 y = - 1 4 x - 5 what is the best description for the lines represented by the equations?