#L10

1. Suppose a disc is rotating counter clockwise in the plane of the paper then1) It's angular velocity vector will be perpendicular to the page pointing up out of the page
2) It's angular velocity vector will be perpendicular to the page pointing inwards
3) It's angular velocity vector acts along the tangent to the disc
4) None of the above is correct​
2.
A circular disc is rotating about its own axis at the rate of 200 revolutions per minute. Two particles P.Q of disc are at distances 5 cm,10 cm from axis of rotation, The ratio of angular velocities of P and Q
(a) 1:2
(b) 1:1
(c) 2:1
(d) 4:1
3. A circular disc is rotating about its own axis at uniform rate completes 30 30 rotations in one minute.The angular velocity of disc in rad s − 1 𝑠 - 1 is A. 2 π 2 𝜋 B. π 𝜋 C. π 2 𝜋 2 D. π
5.A stationary wheel starts rotating about its own axis at uniform angular acceleration 8 rad/s2
. The time taken by it to complete 77 rotations is
A. 5.5 sec
B. 7 sec
C. 11 sec
D. 14 sec
6.A stationary wheel starts rotating about its own axis at a constant angular acceleration. If the wheel completes 50
rotations in the first 2s
, then the number of rotations made by it in the next 2s
is:
A.50B.100C.125D.150
7.Question
A particle is moving along a circular path with uniform speed. Through what angle does its angular velocity changes when it completes half of the circular path?
A
0
∘
B
45
∘
C
180
∘
D
8.If angular velocity of a disc depends an angle rotated θ 𝜃 as ω = θ 2 + 2 θ 𝜔 = 𝜃 2 + 2 𝜃 , then its angular acceleration α 𝛼 at θ = 1 𝜃 = 1 rad is : A. 8 r a d / s 2 8 𝑟 𝑎 𝑑 / 𝑠 2 B. 10 r a d / s 2 10 𝑟 𝑎 𝑑 / 𝑠 2 C. 12 r a d / s 2 12 𝑟 𝑎 𝑑 / 𝑠 2 D. None of these
9.A body is executing circular motion in the vertical plane containing directions. If the direction of velocity v⃗
at the top most point is towards the west, what is the direction of angular velocity ω⃗
?
A. East
B. West
C. North
D. South
10.A horizontal circular plate is rotating about a vertical axis passing through its center with an angular velocity ω0
. A man sitting at the center having two blocks in his hands stretches out his hands so that the movement of inertia of the system doubles. If the kinetic energy of the system is K
initially, its final kinetic energy will be:
A. 2K
B. K2
C. K
D. K4