Physics question PLEASE?

Question

Why is it easier to push or pull an object up an incline rather than lift it vertically?

Please explain clearly and include a simple diagram to help me see it, if you can. Thank You!

Answer 1

it is easier because the incline or ramp gives you an advantage. just like a pulley or a leaver.

so when you push or pull you put in less energy to move the object and you don't get tired.

but you DO travel longer because the ramp takes more lenght.

jani

Answer 2

Although I cannot draw a picture myself, you can refer to the picture sourced below and I will try to explain what is going on.

When you lift an object vertically, you have to exert a force equal to the weight of the object.  Say an object weights 100 Newtons, then you would need to lift with at least 100 N (a little more to actually get it moving) to raise it off the ground.

Note that weight is equal to mass * acceleartion of gravity or mg.  (This is the symbology shown in the source below).

When you are pushing an object up an inclined plane, much of the weight is taken up by the plane (just like the floor supports the weight of the object).  Looking at the diagram, the weight of the object exerts a normal force on the plane as well as a force parallel to the plane (both vector components of the weight force shown by dotted blue lines).  When you add these two forces together, you get the resulting weight.

To get the object to move up the ramp, all you need to do is provide a force parallel to the ramp that exceeds the parallel force component of the weight, which would be equal to Wsin(a) where W is the weight of the object and a is the angle of the plane.  From this we see that the smaller the angle, the less force you would need to set the object in motion.

Note that this responce neglects static and dynamic friction, which would actually resist the force to push the object up the incline.  This can be considered negligable if the object is on a well lubricated trolley!  To consider it, you would just need to add a uWcos(a) to the force, where u is the coefficient of friction.

Answer 3

When you push up an incline vs. deadlift it is not only less steep, the surface bears some weight. However, there is no surface friction to overcome in a deadlift, so its almost a wash. Its easier for a person to raise an object using an incline because it is better suited to human physiology, leverage being the biggest advantage.