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Julie carries an 8.0-kg suitcase as she walks 18 m along an inclined walkway to her hotel room at a constant speed of 1.5 m/s. The walkway is inclined 15 degrees above the horizontal. How much work does Julie do in carrying her suitcase?
Julie carries an 8.0-kg suitcase as she walks 18 m along an inclined walkway to her hotel room at a constant speed of 1.5 m/s. The walkway is inclined 15 degrees above the horizontal. How much work does Julie do in carrying her suitcase?

Respuesta :

MissPhiladelphia
In physics, a force is said to do work if, when acting, there is a displacement of the point of application in the direction of the force. For example, when a ball is held above the ground and then dropped, the work done on the ball as it falls is equal to the weight of the ball (a force) multiplied by the distance to the ground (a displacement). so in the proble, She does NO work since the force she applies to the case is vertical and the direction of motion is horizontal. Work is the force times the parallel distance

Answer:

[tex]W = 365.7 J[/tex]

Explanation:

As we know that work done is defined as the product of force and its displacement in the direction of the force

So here we know that

applied force by Julie is same as that of weight of her suitcase

So we will have

[tex]F = mg[/tex]

[tex]F = (8\times 9.81)[/tex]

[tex]F = 78.48 N[/tex]

now we know that the total height to which the suitcase is raised is given as

[tex]H = L sin\theta[/tex]

[tex]H = 18 sin15[/tex]

[tex]H = 4.66 m[/tex]

now the work done is given as

[tex]W = F.d[/tex]

[tex]W = 78.48(4.66)[/tex]

[tex]W = 365.7 J[/tex]

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