Question

Consider a system of an 85.0 kg man, his 21.0-kg dog, and the earth. The gravitational potential energy of the system increases by 2.40 103 J when the man climbs a spiral staircase from the first to the second floor of an apartment building. If his dog climbs a normal staircase from the same first floor to the second floor, by how much does the potential energy of the system increase (in J)?

Answer 1

593 J

Step-by-step explanation:

The change in the potential energy (PE) can be calculated using the following expression.

PE = m × g × h

where,

m: mass

g: acceleration due to the gravity

h: height (vertical distance from the first floor to the second floor)

For the 85.0-kg man,

PE = m × g × h

2.40 × 10³ J = 85.0 kg × 9.81 m/s² × h

h = 2.88 m

For the 21.0-kg dog,

PE = m × g × h

PE = 21.0 kg × 9.81 m/s² × 2.88 m = 593 J