Qualification > Sciences
Edexcel PHYSICS Doubts
astarmathsandphysics:
A ceiling fan is turning at a rate of 100 revolutions per minute. A spider is clinging to a blade of the fan. If the spider experiences a centripetal acceleration greater than 0.3g, it will lose its grip on the blade and be flung
off. How far from the centre of the fan can the spider safely go?
need to know mass of s[ider
astarmathsandphysics:
sorry misread question
a=v^2/r ==(2 pi r f)^2/r =4 pi^2 f^2 r =0.3g so r=0.3g/(4 pi^2 f^2)=2.94/(4 pi^2 *(100/60)^2) = 0.026 m
astarmathsandphysics:
Whoever can help PLEASE HELP !
I have an exam tomorrow and I need someone to explain to me why I got my answers wrong.
I got 2/10 in the June 2011 Section A
ALL Question in Section A EXCLUDING Q.5 and 10.
so Please help !
lokking now
astarmathsandphysics:
jun 11 answers
1. D since f=ma=m dv/dt= d(mv)/dt= rate of change of momentum. F is equal to the weight.
2. A applying the left hand rule around the loop shows the force always inwards
3. C s since time in seconds
4.C flux linkage is BAN =0.002*0.0004*50
5. D. since gravity mg acts down and centrifugal force=mv^2/r acts up
6. B lenz's law - if the switch is opened the current is Y decreases so the current in X increases to maintain the current in Y
7.mv^2/r=Bev so v=Ber/m=0.02*1.6*10^-19*1.5/(1.67*10^-27)=2.9*10^6 B
The Golden Girl =D:
Sir I have more Questions , do u have the time to answer me :-[ :-\
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version