A53 kg person eats a 518 calorie (518 kcal) jelly doughnut for breakfast. (a) how many joules of energy are the equivalent of this jelly doughnut? (b) how many steps must this person climb on a very tall stairway to change the gravita- tional potential energy of the person-earth system by a value equivalent to the food energy in one jelly doughnut? assume the height of a single stair is h = 15 cm. (c) if the human body is only 22% efficient in converting chemical potential energy to mechanical energy, how many steps must the person climb to work off this delicious, amazing breakfast, and how tall of a staircase does this correspond to?

A. 2,168,399.8 J

B. 27832 steps

C. 918.5 m with 6123 steps

Explanation:

A. Since 1 cal equals to 4.1868 joules

B. The change in the gravitational potential energy of the system is given by

Being m the mass of the person, g the gravity constant and z the height difference. The required z is then given by:

Changed to 0.15 m stairs:

C. At 22% efficiency, the values are reduced, since the process is less efficient:

answer: the correct answer id option(d).

explanation:

snell's law refraction:

the angle of refraction =

the angle of incidence =

refractive index of air = = 1

refractive index of glycerol = 1.47

from the given options, the most closest answer to 63.72° is 65° of option (d).