Can a particle have zero acceleration when its velocity is zero?

AI Thread Summary
A particle can have zero acceleration when its velocity is zero, but acceleration can also be non-zero at that instant. When analyzing various combinations of velocity and acceleration, different scenarios arise: a particle can be moving east with increasing velocity (positive acceleration), moving east with decreasing velocity (negative acceleration), or moving with constant velocity (zero acceleration). In contrast, a particle can also be moving west with increasing or constant velocity, or at rest with either positive or negative acceleration. The discussion emphasizes that while acceleration can be zero when velocity is zero, it is not a strict requirement if considered over an instant. Understanding these concepts is crucial for grasping the dynamics of motion.
mini_smurf13
Messages
1
Reaction score
0
1) If the velocity of a particcle is zero, can its acceleration be zero? Explain.

2) Consider the floowing combinations of signs and values for velocity and accleration of a particle with respect to a one-dimensional x axis.

Velocity | Acceleration
  1. + | +
  2. + | -
  3. + | 0
  4. - | +
  5. - | -
  6. - | 0
  7. 0 | +
  8. 0 | -

Describe what a particle is doing in each case, and give a real-life example for an automobile on an east-west one dimensional axis, with east considered the positive direction.​

I do not understand this at all! Please please please please help if you can with as much as you can. ANY help will be greatly appreciated because I have no idea what to do. :confused:
 
Physics news on Phys.org
If the velocity of a particle is zero, it's acceleration must be zero. Backwards: if the acceleration of a particle is zero, it's velocity can either be zero or constant.
 
Alright for question 2 in the first scenario the particle is traveling east and it's velocity is increasing as acceleration is positive. In the second the particle is once more traveling east but it's velocity is decreasing as acceleration is negative. In the third it is traveling east with constant velocity and fourth traveling west with increasing velocity.
Can you begin to get the idea? Hopefully that helps.
 
BTW, must acceleration be zero when at that INSTANT the velocity is zero?
i think no, there can be acceleration when velocity is zero, but when the period of Zero Velocity stretchs for more that an "instant". then yes, acceleration must be zero.
 
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...
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...
Back
Top