gravity and mass (weight) act on the cage. (9.81 = gravity and 1500kg = mass)
force = mass x change in velocity with time
F = m (v1 - v0)/(t1-t0)
f = 1500 x (73.1)/(20)?
v = 1.1 + (3.6 x 20) = 73.1 m/s (this doesn't sound right?)
'for angular motion Newtons 2nd law (F = ma) becomes:
T = Iα
where I = mr^2/2
so this states I need to use T = Iα? But I don't have α, (or T) right?
I would need ω to find the maximum power as P = T x ω
also with ω i can find α?
kgm^2?
the formula is I = mr^2/2, right?
i need to find w1 and w2 don't I, also?
F = ma
a = v x t? = 20 x 4.6 = 92 m/s^2
F = 1500 x 92 = 138000 Nm
Torque = r x F
T = 0.75m x 138000 Nm = 103500 Nm
Applied torque = 103500 Nm + 48 Nm?
d.) total work done
W = Tθ =
= 1500kg x 76rads = 114000 J =...
don't understand what you means regarding working out radians? is θ not in radians unit? meaning the 76 will be in radians already so that will be the final answer?
b. will just be metres?
for torque i have: Iα/inertia. + friction torque (which will be 48Nm) onto final answer
the question a asks for the angle turned.
i have
s = 0.5 (u + v) t
s = 0.5 (1.1 + 4.6) x 20 = 57 (m?)
θ = s/r
= 57(m?)/0.75m = 76 (radians?)
since the question asks for an angle will i need to turn the radians into degrees, if so how?
b.) I = mr^2/2 = 1200 x 0.75^2 / 2 = 337.5
can you...
the answer i got of 76 is that in degrees or radians? if its in degrees it can be left like that and will be the final answer correct?
but for the second part to find omega it will need to be changed to rads if its in degrees correct?
the next part of the question is: the moment of the inertia...
The question states the mass of the lift cable can be neglected. Is that formula you've posted mass x alpha?
Yeah I have. There are other parts to the question than (a.)
Sorry I don't understand that post completely, could you elaborate please?
Thank you very much for helping.
found this..? (top 1)
http://media.wiley.com/Lux/25/329725.image3.png
found an equation: to convert arc length (s) to angle turned (omega) = omega = s/r
using my previous answer... s = 0.5 x (1.1+4.6) x 20 = 57
is it as simple as dividing 57 by the radius? (0.75m) to find the answer to my question?
if so, I've done that calculation 57m/0.75m = 76. is this answer...
the information required I think is the speeds, time and diameter. I have examples of the other questions that accompany this question I'm sure but this part I am lacking examples/information. No there was no answer provided.
the formula to work out the disttance the cage has moved:
s = 0.5 x...
1. A mine cage of mass 1.5 tonnes is accelerated uniformly upwards from a speed of 1.1 m/s to 4.6 m/s in a time of 20 seconds. The winding drum which is 1.5 metres in diameter has a mass of 1.2 tonne and has the dynamic characteristics of a disc.
There is a bearing friction torque of 48 Nm.
For...