Need help in determining normal force the question is from ss krotov

In summary, we have a cylinder of mass m and radius r resting on two supports of the same height. One support is fixed while the other slides with velocity v. We need to determine the normal force N exerted by the cylinder on the stationary support when the distance between the points of contact is r√2. Friction is neglected and the cylinder rolls without slipping. The horizontal component of the cylinder's velocity is v/2.
  • #1
ishanp
2
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cylinder of mass m and radius r rests on two supports of same height. one is fixed other slides with velocity v.determine normal force N by the cylinder on stationary support at the moment when distance between the point of contacts A and B of cylinder and support) is r√2assuming supports were very close to each other at the initial moment. friction between cylinder and support should be neglected.


my attempt;

r^2 +r^2=(r√2)^2

since friction is neglected the forces exerted on cylinder by supports are always normal to its surface they do zero work. only graviy does work on it. since the triangle formed by radii and AB is rt angled other angles are of 45 degree. work done till that moment=mg(r-r√2/2) . i think that the cylinder rolls without slipping about point of contact with stationary axis(A). moment of inertia about it is 3/2mr^2.if i take v=rω and put work equal to KE will get v of centre of mass and then since com moves in circle centered at A
mgcos45-N=mv^2/r ans is not coming
it is my first post here . thanks
 
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  • #2
ishanp said:
cylinder of mass m and radius r rests on two supports of same height. one is fixed other slides with velocity v.determine normal force N by the cylinder on stationary support at the moment when distance between the point of contacts A and B of cylinder and support) is r√2assuming supports were very close to each other at the initial moment. friction between cylinder and support should be neglected.


my attempt;

r^2 +r^2=(r√2)^2

since friction is neglected the forces exerted on cylinder by supports are always normal to its surface they do zero work. only graviy does work on it. since the triangle formed by radii and AB is rt angled other angles are of 45 degree. work done till that moment=mg(r-r√2/2) . i think that the cylinder rolls without slipping about point of contact with stationary axis(A). moment of inertia about it is 3/2mr^2.if i take v=rω and put work equal to KE will get v of centre of mass and then since com moves in circle centered at A
mgcos45-N=mv^2/r ans is not coming
it is my first post here . thanks

problem is 1.45
solution at back says horizontal component of cylinder's velocity is v/2 .
i don't know how
 

FAQ: Need help in determining normal force the question is from ss krotov

What is normal force?

Normal force is the force exerted by a surface on an object in contact with it. It is perpendicular to the surface and prevents the object from passing through the surface.

How do you determine normal force?

The normal force can be calculated using the formula: N = mg + ma, where m is the mass of the object, g is the acceleration due to gravity, and a is the acceleration of the object in the direction perpendicular to the surface.

Why is normal force important?

Normal force is important because it allows objects to remain in contact with a surface, preventing them from falling through or sliding off. It also plays a crucial role in calculating the net force and determining the motion of an object.

What factors affect normal force?

The factors that affect normal force include the mass of the object, the acceleration of the object, and the angle at which the object is placed on the surface. Additionally, the coefficient of friction between the object and the surface can also impact the normal force.

Are there any real-life applications of normal force?

Yes, normal force is present in many everyday situations. For example, when you sit on a chair, the normal force from the chair supports your weight. In car accidents, the normal force from the seatbelt helps to keep you in place. In sports like rock climbing, the normal force from the wall allows you to push against it and move upwards.

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