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3 years ago

You pick up a 10-newton book off the floor and put it on a shelf 2 meters high. How much work did you do?

Physics

2 answers:

77julia77 [94]3 years ago

5 0

Answer:

20 J of work is done by you, against gravity

Explanation:

Work done by gravity = Potential energy stored in the book after it is put ona shelf.

Potential energy stored:

$U = mgh$

$U = wh$

w= weight in Newton

m= mass of the book

g= acceleration due to gravity

h= height through which, it is raised.

Work is being done against gravity.

$U = 10 \times 2$

$U = 20 J$

Murljashka [212]3 years ago

3 0

Answer:

20 J

Explanation:

Given:

Weight of the book is, $W=10\ N$

Height or displacement of the book is, $d=2\ m$

The work done on the book to raise it to a height of 2 m on a shelf is against gravity. The gravitational force acting on the book is equal to its weight. Now, in order to raise it, an equal amount of force must be applied in the opposite direction.

So, the force applied by me should be equal to weight of the body and in the upward direction. The displacement is also in the upward direction.

Now, work done by the applied force is equal to the product of force applied and displacement of book in the direction of the applied force.

Therefore, work done is given as:

$Work=W\times d\\Work=10\times 2=20\ J$

Therefore, the work done to raise a book to a height 2 m from the floor is 20 J.

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First law of equilibrium

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Answer:

For an object to be an equilibrium it must be experiencing no acceleration.

Explanation:

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3 years ago

The tsunami described in the passage produced a very erratic pattern of damage, with some areas seeing very large waves and near

Lunna [17]

Answer:B. The superposition of waves from the primary source and reflected waves produced regions of constructive and destructive interference.

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3 years ago

Consider a motor that exerts a constant torque of 25.0 nâ‹…m to a horizontal platform whose moment of inertia is 50.0 kgâ‹…m2. A

Crazy boy [7]

Answer:

W = 1884J

Explanation:

This question is incomplete. The original question was:

Consider a motor that exerts a constant torque of 25.0 N.m to a horizontal platform whose moment of inertia is 50.0kg.m^2 . Assume that the platform is initially at rest and the torque is applied for 12.0rotations . Neglect friction.

How much work W does the motor do on the platform during this process? Enter your answer in joules to four significant figures.

The amount of work done by the motor is given by:

$W=\Delta K$

$W= 1/2*I*\omega f^2-1/2*I*\omega o^2$

Where I = 50kg.m^2 and ωo = rad/s. We need to calculate ωf.

By using kinematics:

$\omega f^2=\omega o^2+2*\alpha*\theta$

But we don't have the acceleration yet. So, we have to calculate it by making a sum of torque:

$\tau=I*\alpha$

$\alpha=\tau/I$ => $\alpha = 0.5rad/s^2$

Now we can calculate the final velocity:

$\omega f = 8.68rad/s$

Finally, we calculate the total work:

$W= 1/2*I*\omega f^2 = 1883.56J$

Since the question asked to "Enter your answer in joules to four significant figures.":

W = 1884J

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3 years ago

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3 years ago

Read 2 more answers

A small boy is playing with a ball on a stationary train. If he places the ball on the floor of the train, when the train starts

expeople1 [14]

A small boy is playing with a ball on a stationary train. If he places the ball on the floor of the train, when the train starts moving the ball moves toward the back of the train. This happened due to inertia

An object at rest remains at rest, or if in motion, remains in motion unless a net external force acts on it .

When a train starts moving forward, the ball placed on the floor tends to fall backward is an example of inertia of rest. Due to the reason that the lower part of the ball is in contact with the surface and rest of the part is not . As the train starts moving, its lower part gets the motion as the floor starts moving but the upper part will remain as it is as it is not in contact with the floor , hence do not attain any motion due to the inertia of rest simultaneously i.e. it tends to remain at the same place.

To learn more about inertia here :

brainly.com/question/11049261

#SPJ1

8 0

2 years ago

You pick up a 10-newton book off the floor and put it on a shelf 2 meters high. How much work did you do?​

You pick up a 10-newton book off the floor and put it on a shelf 2 meters high. How much work did you do?