Respuesta :

skyluke89

Answer:

180 W

Explanation:

The work done by the man against gravity is equal to its gain in gravitational potential energy:

[tex]W=mg\Delta h[/tex]

where

(mg) = 720 N is the weight of the man

[tex]\Delta h= 5 m[/tex] is the change in height

Substituting,

[tex]W=(720)(5)=3600 J[/tex]

The power he must deliver is given by

[tex]P=\frac{W}{t}[/tex]

where

W = 3600 J

t = 20 s is the time taken

Substituting,

[tex]P=\frac{3600}{20}=180 W[/tex]

nuhulawal20

The man must deliver a power of 180W, to climb up the ladder.

Given the data in the question

  • Weight of the man; [tex]mg = 720N[/tex]
  • Distance climbed; [tex]d = 5m[/tex]
  • Time take;

First we calculate the work done by the man.

Work done = force × distance

We know that If an object is lifted straight up at constant speed, the force required to lift that object is equal to its weight.

Hence, weight of the man is the same as the force required to life him up the ladder.

[tex]Work \ done = 720N *\ 5m\\\\Work \ done = 3600N.m[/tex]

Now, the power required for this work.

Power is the quantity of energy transferred or converted per unit time

[tex]Power = \frac{Work\ done}{Time}[/tex]

We substitute in our values

[tex]Power = \frac{3600N.m}{20s}\\\\Power = 180N.m/s \\\\Power = 180W[/tex]

Therefore, The man must deliver a power of 180W, to climb up the ladder.

Learn more; https://brainly.com/question/8182768

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