Answer:
The correct option is A
2
Explanation:
The correct option is A
2
π
30
rad s
−
2
Let us assume that the clockwise direction as positive,
it is given that the wheel is rotating with constant angular
velocity
ω
0
=
20
rev min
−
1
We know that,
=
1
rev/ min
=
1
60
rev/s
and we know that
1
complete revolution is
2
π
rad
, so
1
rev /min
=
2
π
60
rad/s
Hence
20
rev min
−
1
=
2
π
3
rad/s
.
It is given that the wheel comes to rest after
10
s
ω
=
0
is the final angular velocity, by the equation of motion
ω
=
ω
0
+
α
t
α
=
−
2
π
30
α
=
2
π
30
rad/s
2