1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
elena-14-01-66 [18.8K]
2 years ago
13

In the pulley system shown below, a 360 N weight is slowly lifted. Assuming the system is 100% efficient and each pulley is weig

htless, what is the minimum input force needed to lift the weight? Rope Pile L= 16.74m
A. 61 N
B. 121 N
C. 181 N
D. 361 N
Physics
2 answers:
STALIN [3.7K]2 years ago
8 0
Your answer is D. 361 N
Sveta_85 [38]2 years ago
7 0

Answer:

A. 61 N

Explanation:

In this system, there are three moveable pulleys. In this case, the rope will have to move six times as far as the weight will rise. In other words, the input distance is 6 times the output distance  ( d in =6⋅ d out ) . Because the efficiency is 100%, the work input is equal to the work output, so we have:

work input  = work output

f( in)  ⋅  d( in) =   f( out)  ⋅  d( out)

 f( in)  ⋅ (6 ⋅  d( out))  =  f( out)  ⋅  d( out)

 f( in)  ⋅ 6 =  f( out)

  f( in)  ⋅ 6 = 360 N

  f( in)  = 60 N  

Another way to think of this is that since the rope has to move 6 times as far as the height of the weight, the mechanical advantage will be 6. Therefore, the input force needed is  360 ÷ 6 = 60 N . Of course, 60 N will balance the object, so a force slightly greater than 60 N (like 61 N) will be required to lift it.

You might be interested in
Please help on this one someone
Nonamiya [84]

Valence electrons are the electrons in the outermost energy level of an atom — in the energy level that is farthest away from the nucleus.

I think it's A.

6 0
3 years ago
Two small spheres with mass 10 gm and charge q, are suspended from a point by threads of length L=0.22m. What is the charge on e
Nataliya [291]

Answer:

q=1.95*10^{-7}C

Explanation:

According to the free-body diagram of the system, we have:

\sum F_y: Tcos(15^\circ)-mg=0(1)\\\sum F_x: Tsin(15^\circ)-F_e=0(2)

So, we can solve for T from (1):

T=\frac{mg}{cos(15^\circ)}(3)

Replacing (3) in (2):

(\frac{mg}{cos(15^\circ)})sin(15^\circ)=F_e

The electric force (F_e) is given by the Coulomb's law. Recall that the charge q is the same in both spheres:

(\frac{mg}{cos(15^\circ)})sin(15^\circ)=\frac{kq^2}{r^2}(4)

According to pythagoras theorem, the distance of separation (r) of the spheres are given by:

sin(15^\circ)=\frac{\frac{r}{2}}{L}\\r=2Lsin(15^\circ)(5)

Finally, we replace (5) in (4) and solving for q:

mgtan(15^\circ)=\frac{kq^2}{(2Lsin(15^\circ))^2}\\q=\sqrt{\frac{mgtan(15^\circ)(2Lsin(15^\circ))^2}{k}}\\q=\sqrt{\frac{10*10^{-3}kg(9.8\frac{m}{s^2})tan(15^\circ)(2(0.22m)sin(15^\circ))^2}{8.98*10^{9}\frac{N\cdot m^2}{C^2}}}\\q=1.95*10^{-7}C

5 0
3 years ago
A 1500 kg car skids to a halt on a wet road where μk = 0.47. You may want to review (Pages 141 - 145) . Part A How fast was the
shusha [124]

The car travels at a speed of 25m/s.

<u>Explanation:</u>

Given-

Mass, m = 1500kg

Coefficient of friction, μk = 0.47

Distance, x = 68m

Speed, s = ?

We know,

Force, F = ma

and

F = μ X m X g

Therefore,

μ * m * g = m * a

μ * g = a

Let, g = 9.8m/s²

So,

a = 0.47 * 9.8 m/s^2

a = 4.606m/s^2

We know,

v^2 - u^2 = 2as

where, v is the final velocity

           u is the initial velocity

           a is the acceleration

           s is the distance

If the car comes to rest, the final velocity, v becomes 0.

So,

u^2 = 2 * 4.606 * 68\\\\u^2 = 626.416m/s\\\\u = 25m/s

The car travels at a speed of 25m/s.

6 0
3 years ago
Lana wanted to do an investigation to see what kind of birdseed the birds in her neighborhood like best. She purchased three of
Misha Larkins [42]

Answer:

The level of seed in each feeder

Explanation:

The independent variable is the variable which is the suspected cause of an observation, it is the variable that produce the effect observed in the dependent variable. The dependent variable is the variable that is measured

The independent variable is normally the x-value while the dependent variable is the y-value

In the question, Lana wants to find out the kind of birdseed that the neighborhood birds like (to eat) the most by feeding them different types of birdseed and measuring the level of the birdseed in the feeders at regular intervals

the independent variable is the bird seed types which Lana gives to the birds, to determine the type of bird seeds the birds like

The dependent variable is the level of the seed in the feeder which depends on the type of seeds the birds like.

3 0
3 years ago
Which of the following natural factors is likely to support the formation of an oceanic island?
stepan [7]
The natural factor that is most likely to support the formation of an oceanic island is the rise of magma from the seafloor. Oceanic islands are also otherwise known as volcanic islands. When volcanoes erupt, they create layers of lava that break the surface of the water. When the tops of the volcanoes emerge, an island is created.<span> </span>
4 0
3 years ago
Read 2 more answers
Other questions:
  • When is L larger than XL
    10·2 answers
  • Is the following true or false?
    10·2 answers
  • Radio astronomers detect electromagnetic radiation at a frequency of 42MHz from an interstellar gas cloud. If the radiation resu
    6·1 answer
  • involves removing the top layer of earth, mining the coal, and then replacing the earth back on the surface.
    6·1 answer
  • Two lightbulbs are wired in series and connected to a 12-volt battery. what happens to the current through the battery if a thir
    11·2 answers
  • A speeding motorist traveling with velocity Vm is spotted by a police car. The police car is initially at rest, but the instant
    11·1 answer
  • When a substance changes states, it <br>either or energy​
    15·1 answer
  • Will give big prizes !!
    9·1 answer
  • As a bullet shot vertically upward rises, the kinetic energy of the bullet
    11·1 answer
  • Which option correctly matches the chemical formula of a compound with its name?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!