Share & grow the world's knowledge!
We want to connect the people who have knowledge to the people who need it, to bring together people with different perspectives so they can understand each other better, and to empower everyone to share their knowledge.
A horizontal platform is rotating with uniform angular velocity ω around the vertical axis passing through its centre. At some instant of time, a viscous liquid of mass m is dropped at the centre and is allowed to spread out and finally fall. The angular velocity during this period.
When a horizontal platform rotates uniformly around a vertical axis passing through its center, the addition of a viscous liquid at its center will affect its motion. After the liquid has been dropped, it spreads outward due to the rotation of the platform and the forces of centrifugation. The movemRead more
When a horizontal platform rotates uniformly around a vertical axis passing through its center, the addition of a viscous liquid at its center will affect its motion. After the liquid has been dropped, it spreads outward due to the rotation of the platform and the forces of centrifugation. The movement of the liquid away from the axis of rotation causes a change in the overall distribution of mass, thus increasing the moment of inertia of the platform.
The principle of conservation of angular momentum tells us that if the torques exerted on a system are zero, the total angular momentum of the system is constant. However, this is dependent both on the moment of inertia and angular velocity, so when the moment of inertia increases due to spreading of liquid, the angular velocity has to reduce for maintaining constant angular momentum. This causes a continuous decrease in the rotation speed of the platform as long as the liquid continues spreading outward.
The angular velocity does not remain constant or increase because the redistribution of mass always increases the moment of inertia. This process ensures that the rotation of the platform slows down uniformly over time, illustrating how angular momentum conservation governs such interactions. Thus, the angular velocity of the platform decreases continuously as the liquid spreads outward and eventually falls off.
Click here:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-6/
A wheel has angular acceleration of 3.0 rad/sec² and an initial angular speed of 2.00 rad/sec². In a time of 2 sec, it has rotated through an angle (in radian) of
A wheel rotates from rest at an initial angular speed of 2.00 rad/s with a constant angular acceleration of 3.0 rad/s 2. Over a time interval of 2 s, the total angle through which the wheel rotates can be determined by combining contributions from its initial angular speed and acceleration. The anguRead more
A wheel rotates from rest at an initial angular speed of 2.00 rad/s with a constant angular acceleration of 3.0 rad/s 2. Over a time interval of 2 s, the total angle through which the wheel rotates can be determined by combining contributions from its initial angular speed and acceleration.
The angular displacement depends on two factors: how much the wheel rotates due to its initial speed and how much it accelerates during the given time. The rotation caused by the initial speed is just the product of the angular speed and time, which accounts for a certain number of radians. The additional rotation comes from the angular acceleration, which increases the wheel’s speed over time, causing more rotation.
The total rotation over those 2 s is the sum of these two contributions. In this example, the angle that is rotated solely due to initial velocity is 4 rad; the acceleration adds in an additional 6 rad to the rotation over the same 2 s period. So a total angular displacement of 10 rad would be completed in the 2 s time duration.
This calculation illustrates the combination of the initial angular motion with constant acceleration as leading to an increase in the total angle rotated over time.
Click here :https://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-6/
See lessA circular disc is to be made by using iron and aluminium so that it acquired maximum moment of inertia about geometrical axis. It is possible with
For maximum moment of inertia of a circular disc about its geometrical axis, the arrangement of materials comes into play. Moment of inertia depends on the mass of the material and at what distance from the axis of rotation it is located. Given a certain amount of mass, the greater the distance of tRead more
For maximum moment of inertia of a circular disc about its geometrical axis, the arrangement of materials comes into play. Moment of inertia depends on the mass of the material and at what distance from the axis of rotation it is located. Given a certain amount of mass, the greater the distance of that mass from the axis of rotation, the greater the corresponding contribution to the moment of inertia.
In this case, the disc is made using iron and aluminum. Iron is denser and heavier, while aluminum is lighter. The heavier material should be placed farther from the axis of rotation to get maximum moment of inertia. The moment of inertia increases with the square of the distance from the axis. By placing iron in the outer region of the disc and aluminum closer to the center, the heavier material contributes more effectively to the rotational resistance.
This arrangement ensures the mass farther away from the axis maximizes its contribution to the moment of inertia. Alternatively, placing aluminum on the interior will reduce its less significant contribution to the inertia. Therefore, the optimal setup is to place aluminum at the interior and iron to surround it, thus maximizing moment of inertia.
Click here for more : – https://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-6/
See lessMoment of inertia of a uniform circular disc about a diameter is l. Its moment of inertia about an axis perpendicular to its plane and passing through a point on its rim will be
The moment of inertia of a uniform circular disc depends on the axis of rotation. Considering an axis passing through its center and perpendicular to its plane, the opposition to rotation is minimal compared with when the axis shifts to another location. If the axis is changed so that it is moved toRead more
The moment of inertia of a uniform circular disc depends on the axis of rotation. Considering an axis passing through its center and perpendicular to its plane, the opposition to rotation is minimal compared with when the axis shifts to another location. If the axis is changed so that it is moved to a point on the rim of the disc but remains perpendicular to the plane, the moment of inertia will increase.
This increases because the mass is now farther away from the new axis, making it harder for the disc to rotate. To determine this new moment of inertia, we can use the concept of adding the effect of the shifting axis. This additional factor accounts for how much the mass is distributed away from the original central axis.
The final outcome is that the moment of inertia about the rim is five times the moment of inertia about a diameter of the disc. This gives an idea about how moving the axis away from the center increases rotational resistance significantly. It is quite an important concept in mechanics for predicting the behavior of objects under different rotational conditions and for the design of systems involving rotating components.
Click here for NCERT Solutions:- https://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-6/
See lessIf a sphere is rolling, the ratio of translational energy to total kinetic energy is given by
A rolling sphere without slipping will have the motion of both translational and rotational motion, which are as follows: center of mass, and the rolling around its axis. The kinetic energy of a sphere is found to be both translational as well as rotational. Translational motion depends on its lineaRead more
A rolling sphere without slipping will have the motion of both translational and rotational motion, which are as follows: center of mass, and the rolling around its axis. The kinetic energy of a sphere is found to be both translational as well as rotational. Translational motion depends on its linear velocity while rotational motion is dependent on the angular velocity of the sphere.
The ratio of translational kinetic energy to the total kinetic energy for a rolling sphere is always 10:7. This particular ratio is due to the unique distribution of the sphere’s mass and geometry. A portion of the total energy is dedicated to the translational motion of the center of mass, while the remaining energy contributes to the rotational motion.
Generally, the translational energy is much higher than the rotational energy because the moment of inertia of a sphere is lower compared to the other shapes; hence, the sphere requires much less energy for it to rotate. This way, the rolling motion of the sphere is preserved without slipping.
This ratio is an important concept in physics because it demonstrates the connection between different energies involved in rolling motion. This is particularly helpful in solving problems dealing with energy conservation and dynamics in rolling objects across different surfaces.
Click here : – https://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-6/
See less