Question

The Burj Khalifa in Dubai is the world's tallest building. The structure is 828 m 828 m (2716.5 ft) and has more than 160 stories. A tourist is obviously using the elevator to reach their hotel room and after a long ride finally arrives at the correct floor, where the tourist has − 2.01 × 10 5 J −2.01×105 J of potential energy. If the 86.4 kg 86.4 kg tourist has zero potential energy at the top of the building, how high ( h ) (h) is the hotel room from the ground? The acceleration due to gravity is 9.81 m / s 2 .

Answer 1

Answer:

h = height of the hotel room from the ground floor = 237.4m

Explanation:

Change in Potential Energy of tourist = ΔPE = PE2 – PE1 = mgh

PE1 is the potential energy of tourist at the ground floor

PE1 is the potential energy of tourist at the top (hotel room)

Given

PE1 = − 2.01 × 10⁵ J

PE2 = 0J

PE2 – PE1 = mgh

0 – (− 2.01 × 10⁵ J) = mgh

2.01 × 10⁵ J = 86.4×9.8×h

h = 2.01 × 10⁵/(86.4×9.8) = 237.4m