Recent content by rockinwhiz

  1. R

    Any past physics olympians here?

    That's damn cool!
  2. R

    Any past physics olympians here?

    I really would like to know the process of your preparation... Like how and when you started preparing, what growth you saw in your problem solving capacity and so on. Kindly share about the beautiful journey. If possible, give me some tips/resources as I'm also an aspiring olympian.
  3. R

    When is the rate of change of Kinetic Energy maximum here?

    Actually, the book this is from has generally ambiguous questions, so nothing is really specified as such. But I might look into that case too. However, for now, getting the answer is enough and I gained a lot of insights too. Thanks to all of you.
  4. R

    When is the rate of change of Kinetic Energy maximum here?

    Oh yeah...! Since, ##A=dv/dt=-(g+ \frac {kv} m)##, therefore, ##\dot {K}_E## becomes: $$ \dot {K}_E = -mv \cdot (g+ \frac {kv} m)$$ So, again, differentiating this with respect to ##v## gives ##-mg -2kv=0##, giving: $$ |v|= |- \frac {mg} {2k} | \approx 12.2 m/s$$ Thank you guys so much!
  5. R

    When is the rate of change of Kinetic Energy maximum here?

    I'll try this in a while and reply. Thanks!
  6. R

    When is the rate of change of Kinetic Energy maximum here?

    So, if I'm not wrong, the kinetic energy keeps changing during upward motion. However, during downward motion, eventually the ball will eventually hit the terminal speed, so the kinetic energy will stop changing I guess?
  7. R

    When is the rate of change of Kinetic Energy maximum here?

    A derivative with respect to ##v## here?
  8. R

    When is the rate of change of Kinetic Energy maximum here?

    Rate of change of kinetic energy would be: $$ \frac {d K_E} {dt} \equiv \frac {d(mv^2/2) } {dt} \equiv mv \cdot \frac {dv} {dt}$$ So, I need to maximize this, most probably. So, should I take take another time derivative?
  9. R

    When is the rate of change of Kinetic Energy maximum here?

    Because, ##F=ma=kv##, therefore, ##a=kv/m##. Clearly, the net acceleration ##A=-(g+a)##. Also, ##A=dv/dt=-(g+ \frac {kv} m )##, so cross multiplying and integrating LHS with respect to ##v## and RHS with respect to ##t## gives me: $$ v= e^{ \frac {-tk} m } * (u + \frac {gm} k) - \frac {gm} k $$...
  10. R

    Why does the big block accelerate?

    Okay, I think I see something here. So, the tension in the string would also act on the big block, to drive it in the opposite direction as the top block, I guess? I think that works. That gets me the answer too. But if there are any nuances, then kindly point them out as well. Thank you!
  11. R

    Why does the big block accelerate?

    I think I might've read something like this somewhere. Centre of mass at the start would be somewhere between the three masses, but closer to the big block. At the end, if the big block didn't move, it probably would shift somewhere away from that point. But no external force acts on the system...
  12. R

    Why does the big block accelerate?

    Clearly, in the picture I can see that on the small block on top, tension and gravitational force act. Gravity gets balance by the normal force, so tension is the only force causing acceleration. On the block at the side gravity and tension result in vertical acceleration. However, I do not...
  13. R

    Variable friction on an inclined plane and maximum velocity

    Oh yeah. I guess I'll check it out later. Thanks for everything man.
  14. R

    Variable friction on an inclined plane and maximum velocity

    A big thank you to all of you helping me out.
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