Hi all
I have a revision question I am having some trouble with
A cold room has a wall measuring 5.2m by 2.5m. The wall is constructed of 120mm thick brick on the inside, a cork layer 80mm and a 30mm layer ow wood in the outside. the inside temperature is -4ºC and the outside temperature...
Hi all
Hope some one can help with this
Calculate the increase in kinetic energy due to acceleration?
0.6m diameter Solid cylinder with a mass of 120kg, initial velocity of 20.94 rad/s and final velocity of 146.61 rad/s.
I have found an equation for the kinetic energy lost at...
Hi Tiny-Tim and Quinzio
I am sure that the answer to my question is 17.97Nm
Thank you both very much for your help
Kindest Regards
John
p.s If I am wrong please tell me : )
this is the extract from the book I am using:-
Torque, moment if inertia and angular motion
Torque
From Newton's third law, we know that to accelerate a mass we require a force such that:
F= ma
Now in dealing with angular motion, we know that this force would be applied at a radius r, from...
According to the book I have, inertia = mass x radius^2
so I = mass x raduis^2 = 10.8kgm^2
T= I x acc = 10.8 x 3.142 = 33.93
and
mass x acc x radius^2 = 120kg x 3.142 x .3^2 = 33.93
it gives the same answer, I am not sure what you are telling me
John
Oh yes, whoops.
I have used the following equations to solve the problem:-
200rpm x 2 pi /60 = 20.94 rads/s = initial velocity
1400rpm x 2 pi /60 = 146.61 rads/s = final velocity
then
final velocity - initial velocity/40 seconds = 3.142 rads/s^2 = angular acceleration
then
mass x...
Great
so say the applied torque is 33.93Nm I just simply subtract the frictional torque which is 1Nm giving 32.93Nm?
It seems too simple to be true, but Ill go with it : )
Thanks for you help
Hi Tiny-Tim
I have solved the problem but I can’t work out how to factor in the loss of torque due to friction.
Is it just a case of deducting it from the applied torque?
Hope you can help
Cheers
John
Hi all
getting a bit stuck on this problem:-
a solid cylinder rotating about its polar axis has a mass of 120kg and a diameter of 0.6,. If the bearings provide a frictional torque of Nm, find the torque applied to accelerate the cylinder from 200 to 1400rpm in 40 seconds?
if anyone can...
voltage calculation
Hi, on reflection it isn't very clear. Sorry.
how about this-
500v---\/\R1\/\----X----\/\R2\/\---0v
If R1 = 1Mohm and R2 = 10Kohm
what is the voltage at X?
Or this one -
500v---\/\R1\/\--X--\/\R2\/\--Y--\/\R3\/\--Z--\/\R4\/\---0v
If R1 = 1Mohm, R2 =...