A disk and a ring of the same mass and radius are released from rest at the same

Practice Questions

Q1
A disk and a ring of the same mass and radius are released from rest at the same height. Which one reaches the ground first?
  1. Disk
  2. Ring
  3. Both reach at the same time
  4. Depends on the surface

Questions & Step-by-Step Solutions

A disk and a ring of the same mass and radius are released from rest at the same height. Which one reaches the ground first?
  • Step 1: Understand that both the disk and the ring have the same mass and radius.
  • Step 2: Know that when they are released from the same height, they will both start to fall due to gravity.
  • Step 3: Learn about moment of inertia, which is a measure of how difficult it is to change the rotation of an object.
  • Step 4: Realize that the disk has a lower moment of inertia compared to the ring, meaning it can rotate more easily.
  • Step 5: Understand that because the disk rotates more easily, it will convert more of its potential energy into kinetic energy as it falls.
  • Step 6: Conclude that the disk will reach the ground before the ring because it has a lower moment of inertia.
  • Moment of Inertia – The moment of inertia is a measure of an object's resistance to changes in its rotation. The disk has a lower moment of inertia than the ring, which affects how quickly it can accelerate when rolling.
  • Rolling Motion – When objects roll down an incline, both translational and rotational motion must be considered. The distribution of mass affects the acceleration of the object.
  • Energy Conservation – The total mechanical energy (potential + kinetic) is conserved. The way this energy is converted into translational and rotational kinetic energy differs between the disk and the ring.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely