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Maligayang pagdating sa Imhr.ca, kung saan maaari kang makakuha ng mga sagot mula sa mga eksperto nang mabilis at tumpak. Kumonekta sa isang komunidad ng mga eksperto na handang tumulong sa iyo na makahanap ng eksaktong solusyon sa iyong mga tanong nang mabilis at mahusay. Kumonekta sa isang komunidad ng mga eksperto na handang magbigay ng eksaktong solusyon sa iyong mga tanong nang mabilis at eksakto.

A boy whose mass is 45.0 kg runs up 25 steps each steps 30.0 cm high in 50.0 seconds. Find the power in watts expended by the boy?

Sagot :

Answer:

The power in watts is 66.15 Watts

Explanation:

In this problem, we will use the concept of the work-energy theorem to relate the potential energy of the boy and compute his power in running over the stairs.

Formula to use

a. PE = mgh

b. P = W/t

where

PE     is the potential energy, the unit is in Joules (J)

m      is the mass, the unit is in kg

g       is the pull of the Earth's gravity, 9.8 m/s²

h       is the height, the unit is in meter (m)

P       is the power, the unit is in J/s or Watts

W      is the work, the unit is in Joules (J)

t        is the time, the unit is in seconds

Given information

m = 45 kg

h = 25 x 30 cm = 750 cm = 7.5 m

t = 5.0 s

P = ?

Solving the problem

Let us solve the potential energy of the boy

PE = mgh

PE = (45 kg)(9.8 m/s²)(7.5 m)

PE = 3307.5 J

Now, this energy is also equivalent to work according to the concept of energy-work theorem, therefore, PE = Work, so Work = 3307.5 JJ.

Now, let us solve the power exerted by the boy by running over the stairs using

P = W/t

Substitute the given data

P = 3307.5 J / 50 s

P = 66.15 Watts

Therefore, the power exerted by the boy is 66.15 Watts.

To learn more, just click the following links:

  • Definition of power

      https://brainly.ph/question/1429339

  • Relationship of work and energy

      https://brainly.ph/question/411277

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