53. 0 Over 630 min height, the Burj Khalifa is the world's tallest skyscraper. What is the change in gravitational potential energy of a $20 gold coin [33.5 g) when it is carried from ground level up to the top of the Burj Khalifa? Neglect any slight variations in the acceleration due to gravity. Example 6-10 b) If the coin is dropped out of the top floor window how fast is it traveling when it hits the ground below it you neglect air resistance? c) If the average air resistance force on the coin during the fall is 0.07 Newtons, estimate the speed of the coin when it hits the ground below