Question

when
* A coin is kept at a distance 10cm from the centre of
turn table of radius 1 m just begins to slip,when the turn table
rotates at speed of 90 r.p.m.
Caleulate coefficient of static friction :-
​

Answer 1

Step-by-step explanation:

Given that, r=5 cm=0.05 m,

n=90 r.p.m.=1.5 Hz

Limiting force of static frictions =Centrifugal force

μ

s

mg=mrω

2

∴μ

s

=

g

rω

2

=

g

r(2πn)

2

∴μ

s

=

g

4π

2

n

2

r

=

9.8

4×0.05×(3.14)

2

×(1.5)

2

∴μ

s

=0.4527