Not really. One could be more massive, but on a gentler incline. Or there may be a pulley system involved which gives mechanical advantage to the lighter mass.Balsam said:Homework Statement
In pulley problems, how do you determine the direction of accelleration? My teacher said that acceleration is in the direction of the heavier mass or the steeper incline. Is this true?
You can compare their components of weight along the direction of motion. Whichever is greater will determine the direction of the acceleration.Balsam said:What if you had two objects of equal mass and only one was on an incline?
Kaura said:Just calculate the net force in each direction of the pulley
Make sure to account for friction, gravity, and tension
The side with the most net force should be the side that the system accelerates towards
Doc Al said:You can compare their components of weight along the direction of motion. Whichever is greater will determine the direction of the acceleration.
Even easier: Take a guess as to the direction of the acceleration. Then solve the problem. If your answer is positive, you guessed correct; if negative, you had it backwards.
Doc Al said:You can compare their components of weight along the direction of motion. Whichever is greater will determine the direction of the acceleration.
Even easier: Take a guess as to the direction of the acceleration. Then solve the problem. If your answer is positive, you guessed correct; if negative, you had it backwards.
Not sure what you mean by that.Balsam said:Is this because you're supposed to set the direction of accelleration as positive even if its a direction that's commonly labelled as negative(like west)?
No (if I understand what you mean). What I mean is: Pick a direction for the acceleration and call its magnitude "a". You can apply your sign convention however you want. When you solve for "a" you'll find out whether you've picked the correct direction by its sign.Balsam said:Is this because you're supposed to set the direction of accelleration as positive even if its a direction that's commonly labelled as negative(like west)?
No, because one is on an incline: Only a component of its weight acts along the direction of motion.Balsam said:Won't their components of weight be the same since their weight value is the same?
haruspex said:Not sure what you mean by that.
A good method is to pick a direction as positive for each coordinate. Up and right are the most common choices.
If there is a body that you expect to accelerate to the left, you nevertheless assign it an acceleration variable, a, as its acceleration to the right. In the end you will get a negative value for a.
The benefit of this method is that it helps in getting all the signs right in the equations.
Doc Al said:No (if I understand what you mean). What I mean is: Pick a direction for the acceleration and call its magnitude "a". You can apply your sign convention however you want. When you solve for "a" you'll find out whether you've picked the correct direction by its sign.No, because one is on an incline: Only a component of its weight acts along the direction of motion.
Yes, but as I posted this assumes a very simple arrangement, one in which if one mass moves the other is sure to move the same distance. If there is a system of pulleys in place this might not be the case.Balsam said:So, if only one was on an incline, the object on the incline would have the greater component of weight? And if both masses are on an incline, the mass on the steeper slope would have the greater component of weight?
I feel there is some text missing in there... maybe some unprintable characters. Anyway, I can't decipher the meaning.Balsam said:My teacher said to assign the direction of acceleration as positive- so if
is the direction of acceleration, you would make it positive and makenegative, evern though it's usually the other way around
Just the opposite.Balsam said:So, if only one was on an incline, the object on the incline would have the greater component of weight?
Right.Balsam said:And if both masses are on an incline, the mass on the steeper slope would have the greater component of weight?
You may be puzzled that I confirmed that but @Doc Al contradicted me. For some reason, I took you to mean that the other was on the level, but Dr.A is probably right in assuming you meant the other was hanging freely.Balsam said:So, if only one was on an incline, the object on the incline would have the greater component of weight?
The direction of acceleration is the direction in which an object's velocity is changing. It can be in the same direction as the object's motion, in the opposite direction, or at an angle to the object's motion.
The direction of acceleration is determined by the net force acting on an object. If the net force is in the same direction as the object's motion, then the acceleration will also be in that direction. If the net force is in the opposite direction, the acceleration will be in the opposite direction.
Yes, an object can have a changing direction of acceleration if the net force acting on it is changing. For example, if an object is moving in a circular path, the direction of its acceleration will constantly change as it moves around the circle.
The direction of acceleration can affect an object's motion in several ways. If the acceleration is in the same direction as the object's motion, it will cause the object to speed up. If the acceleration is in the opposite direction, it will cause the object to slow down. If the acceleration is at an angle to the object's motion, it will cause the object to change direction.
Acceleration and velocity are closely related. Acceleration is the rate of change of an object's velocity, so any change in acceleration will result in a change in velocity. If the acceleration is constant, the velocity will change at a constant rate. If the acceleration is changing, the velocity will change at a changing rate.