Mechanical Engineering: Ch 11: Friction (21 of 47) The Wedge: Ex.1 Part 1/2 Pending Motion Up

Visit ilectureonline.com for more math and science lectures!
In this video I will find F=?, force needed to act on an 8 degree wedge to just begin to lift up a block (Part1/2).
Next video in this series can be seen at:
• Mechanical Engineering...

[@KelvinPlayerUnknown]

I am just a fan of this channel. I thinks the reason why there is no reaction of the plane(R) on the right side of the wall is that at the bottom of the block ,the wedge exerts a friction force along the bottom of the block and that is in the negative X direction (to the left). And that friction force directing to the left cause a normal force on the left side of the wall. And since there is no force exerting on block to the positive X-direction, we can assume that there won't be no normal force from the right side of the wall and so there is no friction and the reaction force (R) , can't appear. You can also watch the previous video; The wedge: Basic Concept in this channel. Sorry for my bad english.

[@jonathancohn2340]

your english was perfect bro, thanks for the help

[@thammer302]

I don’t understand how the normal force drawn on the left side is not perpendicular to the surface.

[@hectorcardenas2171]

Exactly!

[@raktimchowdhury8317]

sir, why did you draw the reaction force (R2) to the right side of the normal force in the free body diagram of object D??? I mean why should we diddnt do it to the left side of normal force???

[@KelvinPlayerUnknown]

I am just a fan of this channel. The direction of the friction force from block onto the wedge is to the left as wedge is trying to go to right.The direction of the friction force from the wedge onto block is to the left. So when we draw the space diagram of all the forces acting on block, the wedge exerts a friction force along the bottom of the block and that is in the negative X-direction(to the left). Sorry for my bad english.

[@hectorcardenas2171]

@@KelvinPlayerUnknown Friction forces are supposed to be ALONG the faces, not perpendicular or at a given angle from a face. This is not correct.

[@jrb8955]

I can't sleep and decided to watch some of this, now i can't sleep more

[@hectorcardenas2171]

This analysis is wrong, go to sleep.

[@namugwanyamarypatience7039]

Why did we ignore the friction between the block and the 2 sides of the wall? I expect there to be friction.......

[@MichelvanBiezen]

For simplicity and so we can concentrate on the concept shown. That said, the friction between the wall and the block is very small compared to the friction between the wedge and the block.

[@sunilpandeya3502]

Why not force on left side of block ?

[@MichelvanBiezen]

There is, but we ignore it since there is no friction on the sides.

[@rishirajpaulchowdhury2874]

If there is no friction on the sides, how can R1 be there Sir?

[@alihaider1563]

How do we know if the reaction force make the angle on the right of the normal force or left?

[@MichelvanBiezen]

The reaction force will be the vector sum of the normal force and the friction force.

[@alihaider1563]

Thank you sir

[@amanshah7780]

Thank you very much sir 🙏🏻😊

[@kishorekumar-sm8hu]

very useful thankyou sir