Free Printable Target Physics [XI DPP 41] ROTATION (Rotational Kinetics)

Worksheets

Target Physics [XI DPP 41] ROTATION (Rotational Kinetics)

Total questions: 20

Worksheet time: 10mins

Name

Class

Date

A wheel of mass 2 kg having practically all the mass concentrated along the circumference of a circle of radius 20 cm, is rotating on its axis with an angular velocity of 100 rad/s. The rotational kinetic energy of the wheel is

4 J

70 J

400J

800 J

A rod of length L is hinged from one end. It is brought to the horizontal position and released. The angular velocity of the rod when it is in the vertical position is

\sqrt{\frac{2g}{L}}

$\sqrt{\frac{3g}{L}}$

$\sqrt{\frac{g}{2L}}$

$\sqrt{\frac{g}{L}}$

If a solid sphere, disc and cylinder are allowed to roll down an inclined plane from the same height

cylinder will reach the bottom first

disc will reach the bottom first

sphere will reach the bottom first

all will reach the bottom at the same time

A mass M is moving with a constant velocity parallel to the x axis. Its angular momentum w.r.t. the origin.

is zero

remains constant

goes on increasing

goes on decreasing

A solid homogeneous sphere is moving on a rough horizontal surface, partly rolling and partly sliding. during this kind of motion of this sphere.

total kinetic energy is conserved

angular momentum of the sphere about the point of contact with the plane is conserved

only the rotational kinetic energy about the centre of mass is conserved.

angular momentum about the centre of mass is conserved.

A thin circular ring of mass M and radius r is rotating about its axis with a constant angular velocity ω. Two objects, each of mass m are attached gently to the opposite ends of the diameter of the ring. The wheel now rotates with an angular velocity.

ωM/(M+m)

{(M-2m)/(M+2m)}ω

{M/(M+2m)}ω

{(M+2m)/M}ω

The moment of inertia of a cylinder of radius a, mass M and height h about an axis parallel to the axis of the cylinder and instant b from its centre is

(3/4) Ma²

(2/3)Ma²

(3/2)Ma²

none of these

A thin bar of mass M and length L is free to rotate about a fixed horizontal axis through a point at its end. The bar is brought to a horizontal position and then released. The following statement is true regarding its motion

the angular acceleration of the rod is constant.

The angular momentum about the axis of rotation is constant.

The force exerted by the rod on te hinge of the axis of rotation continuously changes.

The acceleration of the centre of the mass is equal to g.

The ratio of the radii of gyration of a circular disc and a circular ring of the same mass and radius about a tangential axis parallel to the their planes is

6 : 5

1 : 2

5 : 6

none of these

10.

Assuming the mass distribution of the earth to be spherically symmetric, if the radius of the earth contracts to half of its present value, the length of the day will be:

48 hrs

24 hrs

12 hrs

6 hrs

11.

Two uniform solid spheres having unequal masses and unequal radii are released from rest from the same height on a rough incline. If the spheres roll without slipping,

the heavier sphere reaches the bottom first

the bigger sphere reaches the bottom first

the two spheres reach the bottom together

lighter sphere reaches the bottom first

12.

A thin bar of mass M and length L is free to rotate about a fixed horizontal axis through a point at its end. The bar is brought to the horizontal position and then released. The angular velocity when it reaches the vertical position is

directly proportional to its length and inversely proportional to its mass.

independent of mass and inversely proportional to the square root of its length.

dependent only upon the acceleration due to gravity and the length of the bar.

directly proportional to its length and inversely proportional to the acceleration due to gravity.

13.

The ratio of the radii of gyration of a spherical shell and a solid sphere of the same mass and radius about a tangential axis is

\sqrt{3}:\sqrt{7}

$\sqrt{5}:\sqrt{6}$

$\sqrt{25}:\sqrt{21}$

$\sqrt{21}:\sqrt{25}$

14.

Three mass particle A, B and C having masses m, 2m and 3m respectively are rigidly attached to a ring of mass m and radius R which rolls on a horizontal surface without slipping. At a certain instant the velocity of the centre of the ring is v₀ as shown in the figure. The kinetic enegy of the system is

7mv_0^2

$9mv_0^2$

$mv_0^2$

$\frac{7}{2}mv_0^2$

15.

Three mass particle A, B and C having masses m, 2m and 3m respectively are rigidly attached to a ring of mass m and radius R which rolls on a horizontal surface without slipping. At a certain instant the velocity of the centre of the ring is v₀as shown in the figure. The kinetic enegy of the system is

In the above problem, the velocity of the centre of the mass of the system is

v_0

$7v_0$

$\frac{\sqrt{85}}{7}v_0$

$\frac{7}{\sqrt{85}}v_0$

16.

A cylinder rolls up an inclined plane, reaches some height, and then rolls down (without slipping throughout these motions). The directions of the frictional force acting on the cylinder are :

Up the incline while ascending and down the incline descending.

Up the incline while ascending as well as descending.

down the incline while ascending and up the incline while descending.

down the incline while ascending as well as descending.

17.

A circular platform is free to rotate in a horizontal plane about a vertical axis passing through its centre. A tortoise is sitting at the edge of the platform. Now, the platform is given an angular velocity ω₀. When the tortoise moves along a chord of the platform with a constant velocity (with respect to the platform), the angular velocity of the platform ω will vary with time t as

18.

A circular hoop of mass m and radius R rests flat on a horizontal frictionless surface, A bullet, also of mass m, and moving with a velocity v, strikes the hoop and gets embedded in it. The thickness of the hoop is much smaller than R. The angular velocity with which the system rotates after the bullet strikes the hoop is

\frac{V}{4R}

$\frac{V}{3R}$

$\frac{2V}{3R}$

$\frac{3V}{4R}$

19.

A cylinder of radius 10 cm rides between two horizontal bars moving in opposite direction as instantaneous axis of rotation and the angular velocity of the roller are respectively (There is no slipping at P or Q)

8 cm from Q, 1.25 rad /s²

8 cm from Q , 2.50 rad/s²

15 cm from Q 1.25 rad /s²

15cm from Q, 2.50 rad/s²

20.

A uniform rod AB of mass m and length l is at rest on a smooth horizontal surface. A horizontal impulse P is applid to t end B prpendicular to the rod. The time taken by the rod to turn through a right angle is

πmλ/12 P

πmλ/6 P

mλ/6P

none of these

Reset

Target Physics [XI DPP 41] ROTATION (Rotational Kinetics)

Total questions: 20

Worksheet time: 10mins

Similar Resources on Wayground