# Two masses a pulley and an inclined plane find mass

Determine the tension of the rope. For each mass, draw the forces that act on it, choose a reference frame and specify the positive direction of the axes. The blocks are subject to the normal force as they rest on planes. The friction force will also act on the first block. In addition, the weight acts on the blocks because they are close to the Earth.

## Two masses on an inclined plane with a massless pulley

And finally, on each block will act the tension of the rope. Be specific with the notation. Use indexes to identify the bodies subject to the different forces. The different forces of this problem are represented in the following figure. Note that in this figure the magnitude of the tension of the rope is the same for both sides of the pulley. This is always the case if the pulley has a negligible mass. On the other hand, the magnitude of the acceleration of the blocks is the same since they are joined by the rope.

In the figure above you can see that we have chosen a different orientation for the reference frame axes associated with the two masses. In general, when a mass is on an inclined plane, the x-axis is chosen so that it is aligned with the plane. In this way the vector acceleration of the mass needs to be projected only on this axis and its projection corresponds to the magnitude of the vector.

You can orient the axes differently for each of the masses as long as you are consistent with the orientation and the positive direction of the axes you have chosen. From equation 4 we obtain the normal magnitude on block 2, which would be useful, for example, if we had to calculate the friction force in the inclined plane. Ad blocker detected Knowledge is free, but servers are not. Please consider supporting us by disabling your ad blocker on YouPhysics.Hot Threads.

For a better experience, please enable JavaScript in your browser before proceeding. Two Masses, a Pulley, and an Inclined Plane. Thread starter ElectricMile Start date Feb 26, Assume that the blocks accelerate as shown with an acceleration of magnitude a and that the coefficient of kinetic friction between block 2 and the plane is mu.

Express your answer in terms of some or all of the variables a, mu, and theta, as well as the magnitude of the acceleration due to gravity g.

In general when working out problems of this type it is useful to have a plan of attack. And for problems of this type there is definately a common set of steps that will help you get started.

### Two Masses, a Pulley, and an Inclined Plane. help?!?!?!?

A couple of notes: When you are drawing your free-body diagrams remember it is only the forces acting on that body. When you are choosing your coordinate system in physics you are free to choose any coordinate system you like- the trick is using one that makes your life easy typically you will try to choose a coordinate system in which the acceleration is only in one of the dimensions.Hot Threads.

Thread starter JefeNorte Start date Oct 3, Homework Statement A block of mass m resting on a 20 degree slope.

It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass 2. What is the minimum mass m that will stick and not slip? If this minimum mass is nudged ever so slightly, it will start being pulled up the incline. What acceleration will it have? I calculated the tension on the rope by multiplying the mass of the hanging block by 9.

But when I plug these values into the equation I keep getting 2. Is there something wrong with my equations or the tension value? Dick Science Advisor. Homework Helper. The tension in the rope is only equal to the weight of the hanging block if the objects aren't accelerating. Then you have two equations and two unknowns and you solve for T and a. I mean something exactly like that. You must log in or register to reply here. Related Threads on Two masses on an inclined plane with a massless pulley Two masses on inclined plane with frictionless pulley.

Last Post Nov 19, Replies 6 Views 3K. Two masses two pulleys and an inclined plane.In the Newton's laws unit, the topic of two-body problems was introduced. A pair of problem-solving strategies were discussed and applied to solve three example problems. Such two-body problems typically involve solving for the acceleration of the objects and the force that is acting between the objects.

One strategy for solving two-body problems involves the use of a system analysis to determine the acceleration combined with an individual object analysis to determine the force transmitted between the objects.

The second strategy involved the use of two individual object analyses in order to develop a system of two equations for solving for the two unknown quantities. If necessary, take the time to review the page on solving two-body problems. This page will build upon the lessons learned earlier in the Newton's Laws unit. In this lesson we will analyze two-body problems in which the objects are moving in different directions. In these problems, the two objects are connected by a string that transmits the force of one object to the other object.

The string is wrapped around a pulley that changes the direction that the force is exerted without changing the magnitude. As an illustration of how a pulley works, consider the diagram at the right. Object A is connected to object B by a string. The string is wrapped around a pulley at the end of a table. Object A is suspended in mid-air while object B is on the table. In this situation, Object A will fall downward under the influence of gravity, pulling downward on one end of the string that it is connected to.

According to Newton's law of action-reactionthis lower end of the string will pull upward on object A. The opposite end of the string is connected to object B. This end of the string pulls rightward upon object B.

As such, the string connecting the two objects is pulling on both objects with the same amount of force, but in different directions. The string pulls upward on object A and rightward on object B. The pulley has changed the direction that the force is exerted. Problems involving two objects, connecting strings and pulleys are characterized by objects that are moving or even accelerating in different directions. They move or accelerate at the same rate but in different directions. As such, it becomes important in approaching such problems to select a different reference frame and axes system for each object.

Attention should be given to selecting an axes system such that both objects are accelerating along an axis in the positive direction.Hot Threads. For a better experience, please enable JavaScript in your browser before proceeding. An inclined plane, a pulley, and three masses. Thread starter smashd Start date Dec 10, Homework Statement A system comprising blocks, a light frictionless pulley, a frictionless incline, and connecting ropes is shown. The 9 kg block accelerates downward when the system is released from rest.

The acceleration of the system is closest to: A. Last edited: Dec 11, After defining your axis, draw the 3 FBD's for the masses, you are on more or less the right track, lets see if we can get to solution here Do the FBD first Thanks for the input, WillemBouwer.

You must log in or register to reply here. Related Threads on An inclined plane, a pulley, and three masses Masses on inclined planes and pulleys! Last Post Feb 20, Replies 2 Views 4K. Masses on incline plane and pulley.Hot Threads.

## Two masses on an inclined plane with a massless pulley

Featured Threads. Log in Register. Search titles only. Search Advanced search…. Log in. Contact us. Close Menu. Support PF! Buy your school textbooks, materials and every day products Here! JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding. How do you find tension and friction on an inclined plane. Thread starter Leah Start date Aug 31, Homework Statement How do you find tension and friction on an inclined plane given acceleration, two masses and an angle?

two masses a pulley and an inclined plane find the mass of block 2 mastering in physics

It's a pulley system, I suppose. Insights Author. Leah said:. That works. Where does that equation come from?

### Two Masses, a Pulley, and an Inclined Plane

You can use this equation to calculate the force from friction and then work backwards to get the coefficient of friction. How would solve it if I had to find the net tension of the two masses? Fnet is not zero. You found tension already.