Movers have to haul a piano up to a window that is 5 floors above the ground. They decide to use a pulley system with 6 strands of rope. if the movers can exert a total force of 1111 N, how heavy a piano can they hoist?
It doesn't say where the movers are standing but I'm assuming on the...
Homework Statement
http://imgur.com/MaT4N
Homework Equations
Torque = Fr
The Attempt at a Solution
1) I tried
m2 g r - m1 g r = 1/2 M r^2 * (acceleration / r)
didn't work
2)I tried replace the moment of inertia equation to above equation,still didn't work
Homework Statement
http://apcentral.collegeboard.com/apc/public/repository/ap04_frq_physics_cm_36191.pdf
The problem can be found here. I am stuck on problem 2 d.
Homework Equations
I = m(g-a)R2 / a //found in part c
The Attempt at a Solution
I don't understand why the...
Homework Statement
In Fig. 9.2, two blocks, of masses 2 kg and 3 kg, are connected by a light string that passes over a pulley of moment of inertia 0.004 kgm^2 and radius 5 cm. The coefficient of friction for the table top is 0.30. The blocks are released from rest. Using energy methods, one...
[b]1. A 2.5 kg block and a 1.5 kg block are attached to opposite ends of a light rope. The rope hangs over a solid frictionless pulley that is 30 cm in diameter and has a mass of .75 kg. When the blocks are released, what is the acceleration of the lighter block.
Ok, the book says 2.2m/s^2...
Homework Statement
A block of mass (m1) is attached by a massless string to a pulley of mass (m2) with radius R. Starting from rest, what is the block's speed after it has fallen height h?
Homework Equations
I'll call angular velocity w.
I'm thinking conservation of mechanical energy, so...
Hi for my design project at uni I am to design a truss crane to a certain spec.
I can easily calculate the forces in a truss without the pulley systems.
However when I have the pulleys I'm not sure how this affects the forces in the truss.
I have the load attached via a 4 cable pulley at the...
Homework Statement
A window washer of mass M is sitting on a platform suspended by a system of cables and pulleys as shown . He is pulling on the cable with a force of magnitude F. The cables and pulleys are ideal (massless and frictionless), and the platform has negligible mass...
Two blocks are connected by a string-one on an incline, the rope draped over a pulley, and one hanging from the string. The smooth inclined surface makes an angle of 35 with the horizontal, and the block on the incline has a mass of 5.7 kg. The mass of the hanging block is 3.2kg. Find the...
Hi there,
If a pulley system made of 2 same mass blocks (on a a table, one hanging), a disk pulley with mass but no friction on the string nor pulley axis, does it mean that the Tension on the rope is the same on either side of the rope? Everywhere I've read implies this, and it makes sense...
I'm just wondering if the tension between the masses, that is the tension from the string, is different between each mass in the following situations. Like is the T between m1 and m2 different from the T between m2 and m3? Is it for both situations or is the T the same all around in one of the...
A window washer pulls himself upward using the bucket pulley apparatus shown. How hard must he pull downward to raise himself at a constant speed? The mass of the person and the bucket is 65kg.
My attempt:
When doing pulley problems, I like to set 'moving to the right' as positive. In this...
Homework Statement
Two blocks are connected by a very light string passing over a massless and frictionless pulley (Figure ). The 20.0-N block moves 75.0cm to the right and the 12.0-N block moves 75.0cm downward. Find the total work done on 20.0-N block if there is no friction between the...
Please refer to problem VI here:
http://www.physics.ohio-state.edu/~dongping/phys131_winter2011/phys131/final-exam-practice-2011.pdf
Use 10 for gravity if needed.
Homework Statement
1. When the system is released from rest, what is the magnitude of the blocks' acceleration?
2...
Hi Guys,
I'm a mechanical engineer looking for help with a structural problem, I work on-site at an iron ore mine in Western Australia. Typically once we design stands we get them fabricated then sent for certification. Certification involves a company putting the load which we wish to get...
Homework Statement
In the figure here three ballot boxes are connected by cords, one of which wraps over a pulley having negligible friction on its axle and negligible mass. The masses are m1 = 28 kg, m2 = 45 kg, and m3 = 12 kg. When the assembly is released from rest, (a) what is the...
Homework Statement
Homework Equations
What happens if you take into consideration the mass of the pulley, the mass of the string, and the force of friction between the string and the pulley when you are doing a Fletcher's trolley question?
The Attempt at a Solution
i know that by taking...
Homework Statement
[PLAIN]http://nicholascrumrine.net/otherpics/physics/HW4_6.jpg
Homework Equations
Sum(F)=MA
w=v/r
The Attempt at a Solution
My assumptions are as follows:
The sum of the tensions on the left side of the pulley is equal to the tension in right side of the...
Homework Statement
A frictionless pulley connects 2 masses, one of which is on a frictionless inclined plane at angle θ, as shown in the diagram. The pulley system is set up so it has a mechanical advantage of 2 (so that if m1 moves 1 meter, m2 will move only 0.5 meters). Find equations...
Homework Statement
A pulley having a rotational inertia of 1.1 10-3 kg·m2 about its axle and a radius of 23 cm is acted on by a force, applied tangentially at its rim, that varies in time as F = 0.50t + 0.30t2, where F is in Newtons and t in seconds. If the pulley was initially at rest, find...
Hello everyone... I need ur help in the following problem
Homework Statement
A perfect rope connects a 20 kg block to a 30 kg block. The rope passes over a perfect
pulley at the top of a 53 ° incline. The 30 kg block rests on the incline and the 20 kg
block hangs from the pulley. The blocks...
Homework Statement
A 12.0kg box resting on a horizontal, frictionless surface is attached to a 5.00kgweight by a thin, light wire that passes without slippage over a frictionless pulley (the figure ). The pulley has the shape of a uniform solid disk of mass 1.70kg and diameter 0.600 m...
Homework Statement
A system has two blocks connected by frictionless pulleys. One block (m = 3kg) is above the other (m = 2kg) vertically, as the other is lowered by a weight. Initially, they are 5m apart, vertically. When the weight is removed, what is the speed of the blocks when they are at...
Homework Statement
A block with mass 10.7 kg is placed on an inclined plane with slope angle 24^\circ and is connected to a second hanging block that has mass 15 kg by a cord passing over a small, frictionless pulley. The coefficient of static friction is 0.47 and the coefficient of kinetic...
EDIT: I just realized I have to use the tension as the force and not simply mg. It's been a while since I dealt with these problems and that slipped my mind. I think I get it now, sorry.
I can't figure out where I'm messing up on this. This is not a homework problem, bear with me as I try...
Homework Statement
M1 and M2 are two masses connected as shown. The pulley is light (massless) and frictionless.
Find the mass M1, given that M2 (3.5 kg) accelerates downwards at 2.77 m/s2, θ is 25o, and μk is 0.37.
Homework Equations
F = ma
F = mg
Ff = μkNThe Attempt at a Solution...
In the figure shown the pulley are frictionless and the system hangs at equilibrium. If w3, the weight of the object on the right is 200N, what are the values of w1 and w2?
http://img228.imageshack.us/i/74717268.png/
http://img228.imageshack.us/img228/2605/74717268.th.png
Uploaded with...
Homework Statement
[PLAIN]http://img703.imageshack.us/img703/3580/12p71.jpg
m1 = 1,378 g. It is free to move along a horizontal, frictionless surface. This block is connected to a second block with mass of m2 = 872 g by a massless string that extends around a massless, frictionless pulley...
Homework Statement
http://img148.imageshack.us/img148/8686/ssslk.png
the two boxes and the pulley have the same mass
I=.5mr^2
the system is accelerating downwards calculate the magnitude of the accelerationHomework Equations
The Attempt at a Solution
I will call the falling one D and the...
Homework Statement
In Figure P4.25, m1 = 10.5 kg and m2 = 3.5 kg. The coefficient of static friction between m1 and the horizontal surface is 0.60 while the coefficient of kinetic friction is 0.30.
If the system is set in motion with m2 moving downward, what will be the acceleration of the...
Homework Statement
In the system shown in the figure , block A has mass = 2.00 , block B has mass = 0.360 , and the rope connecting them has a nonzero mass 0.240 . The rope has a total length 1.10 and the pulley has a very small radius. Let be the length of rope that hangs vertically...
Homework Statement
In the figure, find an expression for the acceleration of m1 (assume that the table is frictionless).Homework Equations
The Attempt at a Solution
That picture of the second mass is stumping me because I have no idea what the heck is going on. It seems as if the second mass...
Homework Statement
A ball (hollow sphere) of radius .11m and mass .444kg is mounted on a frictionless axle. A massless cord is wrapped around the ball supporting an object of mass .02kg. Find the angular acceleration of the wheel, linear acceleration of the object and tension in the cord...
Homework Statement
A 10.0 g mass is tied to a string. The string is attached to a 500.0 g mass and stretched over a pulley , leaving the 10.0 g mass suspended above the floor. Determine the time it will take the 10.0 g mass to hit the floor if it starts out 1.50m above the floor.
Homework...
Homework Statement
The pulley on the drawing has moment of inertia of I=kMR2.
What's the acceleration.
Homework Equations
M=I\alpha
F=ma
The Attempt at a Solution
m_1g-T_1=m_1a
T_2-m_2=m_2a
\mbox{ }R\alpha=a
(T_1-T_2)R=kMR^2\cdot\alpha
all these yield:
a=\frac{g(m_1+m_2)}{kM+m_1+m_2}...
Homework Statement
An object of mass m_1 hangs from a string that passes over a very light fixed pulley P_1. the string connects to a second very light pulley P_2. A second string pases around this pulley with one end attached to a wall and the other to an object of mass m_2 on a...
Homework Statement
The figure above shows an 80 kilogram person standing on a 20 kilogram platform suspended by a rope passing over a stationary pulley that is free to rotate. The other end of the rope is held by the person. The masses of the rope and pulley are negligible. You may use g...
Pretend there are two accelerating masses connected to a massless string with a frictionless pulley between them. How can the frictionless pulley (Rotational inertia and radius given) affect acceleration in any sort of way?
Also, why is the net force equal to Acceleration * (Mass of two...
Homework Statement
two blocks of mass m1 50kg and m2 100kg are connected by a string of negligible mass. The pulley is massless and frictionless. The coefficient of kinetic friction between the 50kg block and the incline is 0.250
the 100kg mass is the hanging mass.
theta is 37.0 deg...
Hi,
So I have a problem with a question upon reviewing a past physics final.
Two boxes are connected by a massless, unstretchable rope that passes over a non-ideal pulley. The radius and mass of the pulley are R = 0.100m and M = 1.75 kg. As the pulley turns, friction at the axle exerts a...
Hi anyone, I'm confused about the magnitudes of the acceleration of the two objects here:
It's been awhile since I try to find the answer on internet, I've found numbers of different answers, so I'd like to know if anyone could help me..
In my imagination, if the bigger object moves by...
Homework Statement
A string is wrapped tightly around a fixed pulley that has a moment of inertia of 0.0352kg/m2; and a radius of 12.5cm. A mass of 423g is attached to the free end of the string. The mass is allowed to fall under the influence of gravity. As the mass falls the string causes the...
Homework Statement
The suspended 2.2 kg mass on the right is
moving up, the 2 kg mass slides down the
ramp, and the suspended 8.9 kg mass on the
left is moving down. There is friction between
the block and the ramp.
The acceleration of gravity is 9.8 m/s2 . The
pulleys are massless and...
Homework Statement
A 28.5 kg block (m1) is on a horizontal surface, connected to a 6.10 kg block (m2) by a massless string. The frictionless pulley has a s R = 0.087 m and a moment of inertia I=0.140 kgm2. A force F = 231.3 N acts on m1 at an angle theta = 30.5°. There is no friction between...
A stepped pulley is essentially a system of connected cocentric disks that have different radii. A stepped pulley (I= 2.0 kg*m^2) is placed on a frictionless axle and then strings are attached to two radii of 20 and 50 cm. The other ends of the strings are attached to a 2.0 and 1.0 kg mass...
Homework Statement
A mass of 0.311kg is attached to one end of a string, and a mass of 0.625kg is handing off the other end. The string goes over a pulley which has friction in its axle.
What is the magnitude of frictional torque required to maintain static equilibrium?
Homework...
Homework Statement
A pulley with mass Mp and a radius Rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot. Mass M2 is larger than mass m1. T3 holds the pulley. The quantities Tn and g are magnitudes.
(Select T-True, F-False, G-Greater...
Homework Statement
Two objects are connected by a light string passing over a light frictionless pulley as shown in the figure. the 5.87 kg object is released from rest at a point 2.55m above the floor. The acceleration of gravity is 9.8 m/s^2. What is the speed of each object at the instant...
Homework Statement
A block of mass m = 9.00 kg is situated on an incline of angle θ = 51.0^{\circ} with coefficient of kinetic friction \mu_k = 0.200, and is connected to a light spring of spring constant k = 40.0 N/m via a light rope passing over a massive pulley as shown. The block is...