Relativistic vs non-relativistic momentum

AI Thread Summary
To find the momentum of a 1g particle moving at half the speed of light, use the non-relativistic formula p=mv and the relativistic formula p=mv/(1-v^2/c^2)^(1/2). Comparing the two results typically involves determining which value is larger or smaller. A more precise approach includes calculating the ratio of classical to relativistic momentum or the percentage difference between them. For this scenario, the relativistic momentum is approximately 4.2% larger than the classical momentum. This analysis highlights the significance of relativistic effects at high velocities.
daisy7324
Messages
2
Reaction score
0
The question ask to find the momentum of a particle with mass 1g moving with half speec of c and then compare the answer with the result using relativistic formula for momentum. Do I just use p=mv for non relativistic and p=mv/(1-v^2/c^2)^1/2 and put them equal to each other to find the relationship? Thanks:biggrin:
 
Physics news on Phys.org
Those are the right formulas. When asked to compare to quantities, usually you can answer that by stating which quantity is bigger, which is smaller etc. That's all they are asking for.
 
If you wanted to be more precise you could find the ratio of classical to relativistic momentum.
 
Or you could find the percentage difference between the two, e.g. "the relativistic momentum is 4.2% larger than the classical momentum."
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top