#Falling blocks on a string physics how to#

You can work with an angle from the vertical without converting it, but that means that you’ll actually need to reverse your sines with cosines, and your cosines with sines. If you’re instead given an angle from “the vertical”, it’s best to convert that to an angle from the horizontal. The sums in a triangle will equal 180 degrees. This is important because friction will be opposite to the direction of movement!Īlso, make sure the angle is given like it is in the diagram, “an angle as measured from the horizontal plane”, or else the trigonometry will be off! We denote T as the force of tension, and Ff as the force of friction.Ĭonsider first that mass 1 slides down the ramp. Vertical acceleration is always “0” because the object is assumed not to “fly off” the ramp. You need horizontal forces for mass 1, vertical forces for mass 1, and vertical forces for mass 2. The first thing is to develop equations for each mass. The “proper” way to solve these problems is to find out which direction the system moves in by using all variables except one of the masses and setting the x-axis acceleration to 0. But there’s an angle present too, so we can’t entirely judge it by the masses of the objects. It could be that mass 2 is very heavy and pulls mass 1 up the ramp OR mass 1 is heavy and slides down the ramp, causing mass 2 to rise up. Mass 2 is hanging down, while mass 1 is on an incline and wants to slide down, but might actually get pulled up instead depending on how heavy mass 2 is.Īn angle, theta, is provided, “a certain angle from the horizontal”.īut, we don’t actually know what the direction the system will move in! There are two masses connected to a pulley. You can even see these kinds of problems on final examinations for physics kinematics/mechanics courses because they test many concepts at once! This is a good physics problem where we use concepts such as an incline (involves trigonometry), friction, gravity, and how pulleys work.

#Falling blocks on a string physics how to#

Home» Math Guides» Masses connected to pulley on inclined slope with static/kinetic friction How to solve physics problems with masses on an inclined slope connected by a pulley, with friction