Calculate Angular Momentum of Falling Ball

In summary, the problem involves a ball of mass m that is attached to a flagpole of length l and angle θ with the horizontal. The ball becomes loose and starts to fall, and the question is asking for the angular momentum of the falling ball with respect to a point on the building. The formula for angular momentum in this situation is L = mrvsinθ, but since the angle between the force downwards and the radius is not given, cosine must be used instead of sine. The correct approach to this question is to use v = at and v = -gt to find the angular momentum formula L = -mlgtcosθ. However, the description of the problem is not clear and may require clarification.
  • #1
UrbanXrisis
1,196
1
A ball of mass m is fastened at the end of a flagpole connected to the side of a tall building at point P. The length of the flagpole is l and [tex]\theta[/tex] is the angle the flagpole makes with the horizontal. The ball becomes loose and starts to fall. What is the angular momentum of the ball about point P?

so angular momentum is L=mrvsin(theta)

in this problem, the angle between force downwards and the radius is not given, but the angle beween the building and the radius is given. Therefore, sine cannot be used. Cosine must be used for this specific problem.

v=at
v=-gt

[tex]L=-mlgtCos\theta[/tex]

is this the correct way to approach this question?
 
Physics news on Phys.org
  • #2
I believe your description of this problem is lacking. I picture a ball that's fastened, and when it becomes unfastened it just falls straight down...
 
  • #3
That's the way I interpreted the question as well. Do you perhaps mean that the flag pole becomes loose and swings down to hit the building? Perhaps then you may be looking for the angular momentum of the ball on the end of the pole...
 
  • #4
I interpreted the problem similarly. Assuming the problem is "What is the angular momentum of the falling ball (with respect to a point on the wall) as a function of time?", then UrbanXrisis's answer is correct. (Maybe he can restate the problem.)
 

Related to Calculate Angular Momentum of Falling Ball

1. What is angular momentum?

Angular momentum is a measure of an object's rotational motion. It is calculated by multiplying the object's moment of inertia by its angular velocity.

2. How is angular momentum related to a falling ball?

In a falling ball, angular momentum is related to the ball's spin as it falls. As the ball falls, its angular velocity increases, resulting in an increase in angular momentum.

3. How do you calculate angular momentum of a falling ball?

The formula for calculating angular momentum of a falling ball is angular momentum = moment of inertia * angular velocity. The moment of inertia is a measure of the object's resistance to rotational motion, while the angular velocity is the rate of change of the ball's rotational position.

4. What factors affect the angular momentum of a falling ball?

The angular momentum of a falling ball is affected by its moment of inertia and its angular velocity. Additionally, factors such as air resistance, wind, and the shape of the ball can also impact its angular momentum.

5. Why is it important to calculate the angular momentum of a falling ball?

Calculating the angular momentum of a falling ball can help us understand and predict its motion. It allows us to analyze the impact of different factors on the ball's rotational motion and make accurate predictions about its trajectory and speed.

Similar threads

  • Introductory Physics Homework Help
Replies
9
Views
744
  • Introductory Physics Homework Help
Replies
3
Views
246
  • Introductory Physics Homework Help
Replies
7
Views
2K
  • Introductory Physics Homework Help
Replies
9
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
5K
  • Introductory Physics Homework Help
10
Replies
335
Views
8K
  • Introductory Physics Homework Help
Replies
14
Views
1K
  • Introductory Physics Homework Help
Replies
18
Views
2K
  • Introductory Physics Homework Help
Replies
11
Views
1K
  • Introductory Physics Homework Help
Replies
12
Views
930
Back
Top