Analyzing Forces on a Hockey Puck

  • Thread starter Thread starter reignofdragons
  • Start date Start date
  • Tags Tags
    Forces
AI Thread Summary
A hockey puck sliding on a smooth ice surface experiences several forces, primarily weight and normal force, due to gravity. Friction is generally considered negligible in this scenario, although some participants suggest a small opposing friction force should be included. The concept of "force of velocity" is clarified as incorrect, as velocity itself is not a force. The discussion concludes that the only significant forces acting on the puck are its weight and the net force, leading to the conclusion that the correct answer is AE. Understanding these forces is crucial for analyzing the puck's motion accurately.
reignofdragons
Messages
3
Reaction score
0
A hockey puck slides along a horizontal, smooth icy surface at a constant velocity as shown.

Draw a free-body diagram for the puck. Which of the following forces are acting on the puck?

1. weight
2. friction
3. force of velocity
4. force of push
5. normal force
6. air drag
7. acceleration


Combinations of answers that were wrong

ABCDEF
ABCE
ACE

I've been at this for awhile and can't picture what's going on. Any help or suggestions are appreciated. Thanks for your time.
 
Physics news on Phys.org
Which do you think are acting on the hockey puck? Never mind the answers that were rejected... what's your feeling as to the right answer?
 
sorry for posting in wrong section

Well...what i thought was

-a puck obviously has weight (1)
-since it's on ice, i think I'm supposed to assume there's no friction (2)
-it has some kind of velocity, so i believe there is a force of velocity (3)
-not sure about force of push...i think we're supposed to assume it's just moving on it's own (4)
-well since there's a weight, which probably means there's a down acceleration due to gravity, there's probably a normal force (5)
-air drag is probably negligible (6)
-not sure what kind of acceleration...since it's moving at a constant rate, i know there's no acceleration in that direction, but what about gravity? (7)
 
reignofdragons said:
sorry for posting in wrong section

Well...what i thought was

-a puck obviously has weight (1)

yup, 1) is definitely right.

-since it's on ice, i think I'm supposed to assume there's no friction (2)

I agree.

-it has some kind of velocity, so i believe there is a force of velocity (3)

But velocity isn't a force... there isn't anything I'm aware of such as a force of velocity...

-not sure about force of push...i think we're supposed to assume it's just moving on it's own (4)

yup... plus I don't think "force of push" is a real force of any kind... a force is a push or a pull... but a "force of push" sounds strange...


-well since there's a weight, which probably means there's a down acceleration due to gravity, there's probably a normal force (5)

Yes, there's definitely a normal force.

-air drag is probably negligible (6)

I'd say air drag is a force acting on the puck... might be negligible... but they haven't explicitly stated anything about it... so I'd say it is there...

-not sure what kind of acceleration...since it's moving at a constant rate, i know there's no acceleration in that direction, but what about gravity? (7)

Yes, there's no acceleration... the normal forces balances gravity... but more importantly acceleration isn't a force...
 
Even if the puck is on ice, I wouldn't automatically assume no friction. Otherwise hockey pucks could be tapped slightly and potentially go across entire arenas. I'd say include at least a small friction force opposing motion.
 
Help

There will be only Weight and Net Force acting on the puck. AE would be your answer.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Calculating Velocity of a Hockey Puck
Replies
1
Views
2K
Newton's Laws -- Resting hockey puck hit with a force
Replies
8
Views
4K
Help Evaluating Mathematical Modelling of Physical Problems
Replies
47
Views
4K
Conservation of Work/Momentum of Puck Sliding Off Plate
Replies
4
Views
2K
How Far Does the Goalie Slide on Ice After Catching a Hockey Puck?
Replies
6
Views
2K
Question about net force/acceleration/constant velocity
Replies
3
Views
3K
Final Velocity of Hockey Puck: 40.0 m/s to ?
Replies
1
Views
2K
Free Body Diagrams for hockey puck
Replies
1
Views
15K
Frictionless puck goes up hill then falls. What's V0?
Replies
10
Views
14K
Calculating Net Forces and Distance Traveled: Hockey Puck Example
Replies
12
Views
7K

Hot Threads

Recent Insights

Back
Top