Question

You have a 17 kg suitcase. A) What work did you do when you slowly lift it 0.80 m upward? B) What work did you do when you lower it 0.80 m?

Answer 1

To solve this problem we will apply the concept related to the work theorem, which indicates that the magnitude of the work done on a body is the product between the force, the distance and the cosine of the angle of the force and the distance, that is,

$W = Fd cos\theta$

Where,

F = Force

d = Distance covered

$\theta =$ Angle between the force and the displacement

PART A) The displacement is vertical so the total distance covered is equivalent to the net value of it, so things would end up being the equation

$W = Fdcos\theta$

$W = mg\Delta y$

$\Delta y =$  Vertical height of the suitcase lifted by the person

m = mass of the suitcase

g = Acceleration due to gravity

Replacing

$W = (17)(9.8)(0.8)$

$W = 133.28J$

Therefore the work done on the suitcase is 133.28J

PART B) The same assessments are made considering now that the displacement is negative to our reference system, that is

$W = mg\Delta y$

$W = (17)(9.8) (-0.8)$

$W = -133.28J$

Therefore the work done on the suitcase is -133.28J

Answer 2

The work product of applied force and the distance through which the body is displaced on which the force is applied.

(a)  Work done when you slowly lift the suitcase 0.80 m upward will be 133.28 J.

(b)  Work done when you slowly lift the suitcase 0.80 m downward will be   -133.28 J.

What is work?

Work is defined as the product of applied force and the distance through which the body is displaced on which the force is applied.

According to the work theorem,

W = Fdscosθ

Where,

F = Force employ in lifting

d is the displacement through suitcase displaced vertically

θ is  the angle between the force and the suitcase displaced vertically

(A) Work done when you slowly lift the suitcase 0.80 m upward will be 133.28 J.

W = Fdscosθ

W = mghcosθ

h is the upward distance traveled by the suitcase

m is the mass of the suitcase

g is the gravitational acceleration

W = mghcosθ

W = 17×0.80×cos90°

W= 133.28 J.

Hence Work done when you slowly lift the suitcase 0.80 m upward will be 133.28 J.

(B) Work done when you slowly lift the suitcase 0.80 m downward will be -133.28 J.

W = -Fdscosθ

W =- mghcosθ

h is the downward distance traveled by the suitcase

m is the mass of the suitcase

g is the gravitational acceleration

W = -mghcosθ

W = -17×0.80×cos90°

W= -133.28 J.

(-ve) shows that work is done in favor of gravity.

Hence Work done when you slowly lift the suitcase 0.80 m downward will be  - 133.28 J.

To learn more about the work refer to the link ;

https://brainly.com/question/3902440