Velocity in certain direction[components]

  • Thread starter Thread starter anigeo
  • Start date Start date
  • Tags Tags
    Velocity
AI Thread Summary
The discussion centers on the relationship between the velocity of a block being dragged by a string and the angle of the string. It clarifies that the block's horizontal velocity is expressed as v/sinθ, as opposed to vsinθ, due to the geometry of the situation involving a right triangle formed by the block and the string. The rate at which the string is pulled directly influences the block's velocity along the surface, leading to the equation VB sinθ = v. This distinction is crucial for understanding how to properly relate the components of velocity in this context. The explanation emphasizes the importance of the angle in determining the correct expression for the block's horizontal velocity.
anigeo
Messages
83
Reaction score
0
could you please tell me why the velocity of the block M along the horizontal direction is v/sinθ and not vsinθ as in the case of components of vectors?
 

Attachments

  • Untitled.jpg
    Untitled.jpg
    6.1 KB · Views: 375
Physics news on Phys.org
anigeo said:
could you please tell me why the velocity of the block M along the horizontal direction is v/sinθ and not vsinθ as in the case of components of vectors?
If I understand your diagram (the block is being dragged by the string along the surface), v is the rate at which the string is being pulled. To relate the speed of the block along the surface to the rate at which the string moves, consider the right triangle formed by the block and the string. Let x be the horizontal distance from block to pulley and z be the length of string between block and pulley. How can you relate those quantities?
 
ok i understand what u say. actually this is also what i thought.so thanks.
but while taking the component of a vector along a direction θ from it we write vcosθ if v is the vector.why is it not applicable here?
 
anigeo said:
but while taking the component of a vector along a direction θ from it we write vcosθ if v is the vector.why is it not applicable here?
The block moves along the horizontal. It's the component of the block's velocity (VB) in the direction of the string that must equal the rate at which the string is pulled:
VB sinθ = v
 

Thread 'Is calling fictitious forces "not real" just about terminology?'

Hi there, im studying nanoscience at the university in Basel. Today I looked at the topic of intertial and non-inertial reference frames and the existence of fictitious forces. I understand that you call forces real in physics if they appear in interplay. Meaning that a force is real when there is the "actio" partner to the "reactio" partner. If this condition is not satisfied the force is not real. I also understand that if you specifically look at non-inertial reference frames you can...
View full post »

Thread 'Derivation of Hamilton's Principle: Questions'

I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
View full post »

Similar threads

B Why in two block systems do both blocks tend to have the same velocity?
Replies
6
Views
1K
B Is velocity ever a scalar quantity?
Replies
48
Views
4K
I Earth's angular velocity when axis is aligned with apparent gravity
Replies
1
Views
1K
B Can energy be decomposed?
Replies
2
Views
1K
How Does the Cross Product Determine the Perpendicularity of Angular Velocity?
Replies
2
Views
1K
Equalization of velocity components and momentum conservation
Replies
16
Views
3K
Calculation of orbital velocity -- Geometrical solution
Replies
14
Views
2K
Rigid Body Rotation relative velocity question
Replies
2
Views
10K
Car in corner -- relative airflow
Replies
20
Views
3K
B What is the Absolute Value of the Normal force on a block on this wedge?
Replies
3
Views
1K

Hot Threads

Recent Insights

Back
Top