Is this anywhere correct? F(t_2-t_1)=m(V_2-V_1) N(s_2-s_1)=(kg)(m/s_2-m/s_1) (kg)((m/s)^2)(s_1)=(kg)(m/s_1) not homogeneous?
@jim_thompson5910 can you help me? :)
What are you trying to show again?
I need to determine whether or not the original equation is dimensionally homogeneous.
So the original equation is F(t_2-t_1)=m(V_2-V_1)
correct?
yes
t_2 and t_1 are times in seconds so t_2 - t_1 is a time in seconds
So F(t_2-t_1)=m(V_2-V_1) becomes F(seconds - seconds)=m(V_2-V_1) which becomes F(seconds)=m(V_2-V_1)
Same idea with V_2 and V_1, but these are velocities in m/s V_2-V_1 m/s - m/s m/s Note: m and s are NOT variables, they are units, so m/s is NOT a variable...it's a unit So we get F(seconds) = m(m/s) Do you see how I'm getting all this?
yes, I understand that. Then, F= (kg)(m/s)^2... So, (kg)(m/s)^2(s)=(kg)(m/s) right?
Units for force F = Newtons F = kg*(m/s^2) t_2 and t_1 = seconds (s) V_2 and V_1 = m/s m = kg Sadly there are two 'm' terms here, one for meters and one for mass...hopefully that's not too confusing -------------------- F(t_2-t_1)=m(V_2-V_1) F(seconds) = kg(m/s) (kg*(m/s^2))(seconds) = kg(m/s) (kg*(m/s^2))(s) = kg(m/s) kg*m/s = kg*m/s So the dimensions match
Oops, I meant to write "Units" instead of "units for force", but you get the idea
(kg*(m/s^2))(s) = kg(m/s) kg*m/s = kg*m/s how'd you go front that to that?
The s^2 in the denominator and the 's' in the numerator on the left side multiply and one pair of 's' terms cancel So (1/s^2)*(s/1) = 1/s
That's how (kg*(m/s^2))(s) simplifies to kg*m/s
oh okay gotcha. and one more I did, but I'm unsure if it's correct... F=mV (kg*(m/s^2))=(kg*(m/s)) not homogeneous?
no it's not, the left side has a s^2 in the denominator but the right side only has 's' in the denominator so it's not homogeneous
okay, so yay got one right lol! thanks for the help. greatly appreciated.
you're welcome
Join our real-time social learning platform and learn together with your friends!