Mass of object (wave nature of matter)

AI Thread Summary
The discussion revolves around calculating the mass of an object given its wavelength and speed. The formula used is m = h / (λv), where h is Planck's constant. The initial calculation yielded a mass of approximately 6.577 x 10^-26 kg, but it was noted that the denominator needed proper parentheses for clarity. The final mass, adjusted for significant figures, is confirmed to be 6.58 x 10^-26 kg. The participants agree on the correctness of the logic and calculations, with a reminder to consider significant digits.
quicksilver123
Messages
173
Reaction score
0

Homework Statement



An object has a wavelength of 8.4*10^-14 m
and a speed of 1.2*10^6 m/s.
Find the mass.

Homework Equations



p=h/λ

The Attempt at a Solution



p=h/λ
mv=h/λ
m=h/λv

m=(6.63*10^-34)/((1.2*10^5)(8.4*10^-14))
m=6.577380952*10^-26 kg

Is this correct? (other than significant digits)
 
Last edited:
Physics news on Phys.org
the arithmetic works out correctly but your m=(6.63*10^-34) / ( (1.2*10^5) * (8.4*10^-14) ) equation
needs some parens in the denominator.

You must adjust m for significant figures to be m=6.58 E -26 kg

Also your logic looks right too, but being out of physics for a long time I'd wait for someone to second my opinion.
 
Last edited:
fixed. as i mentioned in the op i haven't yet adjusted for sig dig
 
quicksilver123 said:
fixed. as i mentioned in the op i haven't yet adjusted for sig dig

okay didnt see it. tunnel vision sometimes.
 
thats cool thanks for checking anyway
 
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