Ask question

Ask question

All categories

3 years ago

12

You are moving into an apartment and take the elevator to the 6th floor. Suppose your weight is 790 N and that of your belonging

s is 960 N. (a) Determine the work done by the elevator in lifting you and your belongings up to the 6th floor (15.2 m) at a constant velocity. (b) How much work does the elevator do on you alone (without belongings) on the downward trip, which is also made at a constant velocity?

1 answer:

aliina [53]3 years ago

7 0

Answer:

a) $W=26600J$

b) $W=-12008J$

Explanation:

Given the information from the exercise we can calculate the work done by the elevator using the following formula:

$W=F*s$

a) Considering you and your belongings as a system we know that the elevator is applying a Normal reaction force of:

$F=790N+960N=1750N$

Since the force applied and the displacement is in the same direction, the work done by the elevator is positive

$W=(1750N)(15.2m)=26600J$

b) The reaction force applied by the elevator is the same as the weight of the person

$F=790N$

Since the force applied and the displacement is in opposite direction, the work done by the elevator is negative

$W=-(790N)(15.2m)=-12008J$

You might be interested in

Two men, Joel and Jerry, each pushes an object that are identical on a horizontal frictionless floor starting from rest. Joel an

Nataliya [291]

Answer:

The work done by Joel is greater than the work done by Jerry.

Explanation:

Let suppose that forces are parallel or antiparallel to the direction of motion. Given that Joel and Jerry exert constant forces on the object, the definition of work can be simplified as:

$W = F\cdot \Delta s$

Where:

$W$ - Work, measured in joules.

$F$ - Force exerted on the object, measured in newtons.

$\Delta s$ - Travelled distance by the object, measured in meters.

During the first 10 minutes, the net work exerted on the object is zero. That is:

$W_{net} = W_{Joel} - W_{Jerry}$

$W_{net} = F\cdot \Delta s - F\cdot \Delta s$

$W_{net} = (F-F)\cdot \Delta s$

$W_{net} = 0\cdot \Delta s$

$W_{net} = 0\,J$

In exchange, the net work in the next 5 minutes is the work done by Joel on the object:

$W_{net} = W_{Joel}$

$W_{net} = F\cdot \Delta s$

Hence, the work done by Joel is greater than the work done by Jerry.

7 0

3 years ago

If Cell fragments are found in a rock sample it was most likely that The Rock formed

Ira Lisetskai [31]

5 is 4) shallow water, 6 is 2)sedimentary i think but I'm not 100% sure and 7 is 21%

7 0

3 years ago

A heliocentric system is _____-centered.<br><br> Milky Way<br> Earth<br> Moon<br> Sun

madreJ [45]

Answer: Sun

Explanation:

7 0

3 years ago

Read 2 more answers

Why are images reflected from a rough surface not as clear as those reflected from a smooth

ioda

Answer:

Just as images are reflected from the surface of a mirror, light reflected from a smooth water surface also produced a clear image. ... Consequently, the outgoing rays are reflected at many different angles and the image is disrupted. Reflection from such a rough surface is called diffuse reflection and appears matte.

Explanation:

hi po I hope it's help you

7 0

3 years ago

Write a question about how changing temperature affects gas

Lera25 [3.4K]

Answer:

"How does the volume of a gas kept at constant pressure change as its temperature is increased?"

Explanation:

One possible question can be:

"How does the volume of a gas kept at constant pressure change as its temperature is increased?"

The answer to this question is contained in Charle's law, which states that for a gas at constant pressure, the volume of the gas is proportional to its absolute temperature:

$V\propto T$

Or also written as

$\frac{V}{T}=const.$

By looking at this equation, we can find immediately the answer to our question: as the (absolute) temperature of the gas increases, the volume increases as well, by the same proportion.

3 0

3 years ago