Calculating Incline Distance for Rotational Motion

In summary, the conversation discusses the calculation of how far a hollow cylinder will go up an incline after rolling at a constant speed of 3.3 m/s on a horizontal surface. While the initial approach of using kinetic energy to solve the problem may seem correct, it is important to also consider both rotational and translational kinetic energy in the calculation. This results in a final answer of 4.3 meters, which differs from the initial calculation of 0.56 meters.
  • #1
fizzzzzzzzzzzy
44
1
A hollow cylinder(hoop) is rolling on a horizontal surface at v = 3.3 m/s when it reaches an incline of 15 degrees. how far up the incline will it go?

this was in the chapter about rotational motion but from my understanding of it, it can be solved just by taking the kinetic energy and having it equal the potential energy. when i did that the answer i got was 0.56 meters but the answer in the book is 4.3, I am guessing that what i did doesn't work. Anyone care to explain?
 
Physics news on Phys.org
  • #2
Did you take into account both rotational and translational kinetic energy?
 
  • #3


It is important to consider the conservation of energy in this situation. While it is true that the kinetic energy at the bottom of the incline will be equal to the potential energy at the top, there are other factors at play that need to be taken into account. The energy of the system is not just dependent on the rotational motion of the cylinder, but also the translational motion. When the cylinder reaches the incline, it will start to roll up the incline while also continuing to move forward. This means that the kinetic energy will not just be dependent on the rotational velocity, but also the linear velocity. Additionally, there may be friction present on the incline, which will also affect the energy of the system. Therefore, a more comprehensive approach, taking into account all of these factors, is needed to accurately calculate the distance the cylinder will travel up the incline. This may involve using equations for both rotational and translational motion, as well as considering the effects of friction.
 

1. What is rotational motion?

Rotational motion is the movement of an object around an axis or center point. This type of motion is characterized by the object's angular velocity, which measures the rate of rotation, and its moment of inertia, which measures the object's resistance to changes in its rotational motion.

2. What is the difference between linear and rotational motion?

Linear motion is the movement of an object in a straight line, while rotational motion is the movement of an object around an axis. In linear motion, the object's velocity and acceleration are along the same line, while in rotational motion, the object's angular velocity and angular acceleration are perpendicular to each other.

3. What is angular velocity?

Angular velocity is a measure of the rate of change of an object's angular displacement. It is a vector quantity and is usually expressed in radians per second. It is calculated by dividing the change in angular displacement by the change in time.

4. What is moment of inertia?

Moment of inertia is a measure of an object's resistance to changes in its rotational motion. It depends on the object's mass, shape, and distribution of mass around its axis of rotation. The larger the moment of inertia, the more difficult it is to change the object's rotational motion.

5. How is rotational motion related to torque?

Torque is a measure of the force that causes an object to rotate around an axis. The greater the torque, the more an object's rotational motion will change. This relationship is described by Newton's second law of motion, which states that the net torque on an object is equal to the product of its moment of inertia and its angular acceleration.

Similar threads

  • Introductory Physics Homework Help
Replies
21
Views
1K
Replies
24
Views
1K
  • Introductory Physics Homework Help
Replies
11
Views
2K
  • Introductory Physics Homework Help
Replies
33
Views
977
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
1K
Back
Top