Download App

Systems of Particles and Rotational Motion — Physics STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 SciencePhysicsSystems of Particles and Rotational Motion3 Marks
Question
A solid cylinder of mass 20kg rotates about its axis with angular speed 100rads-1. The radius of the cylinder is 0.25m. What is the kinetic energy associated with the rotation of the cylinder? What is the magnitude of angular momentum of the cylinder about its axis?
✓

Answer

Mass of the cylinder, m = 20kg
Angular speed, $\omega= 100\text{rads}^{-1}$
Radius of the cylinder, r= 0.25m
The moment of inertia of the solid cylinder,
$\text{I}=\frac{\text{mr}^2}{2}$
$=\frac{1}{2}\times20\times(0.25)^2$
$=0.625\text{kgm}^2$
$\therefore$ Kinetic energy $=\frac{1}{2}\text{I}\omega^2$
$=\frac{1}{2}\times6.25\times100^2=3125\text{J}$
$\therefore$ Angular momentum, $\text{L} = \text{I}\omega = 6.25\times100 = 62.5\text{Js}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from Systems of Particles and Rotational Motion→Systems of Particles and Rotational Motion — all question types→Physics STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

A horizontal force of 500N pulls two masses 10kg and 20kg (lying on a frictionless table) connected by a light string as shown. What is the tension in the string? Does the answer depend on which mass the pull is applied?

→
An electric bulb of volume 250cm3 was sealed off during manufacture at a pressure of 10-3 mm of Hg at 27°C. Find the number of air molecules in the bulb.
→
Find the difference in temperature across the surfaces of an iron plate 5 cm thick, through 100 sq. m of which heat flows at the rate of 9.6 ×105 J/s.
[Take K = 96 Wm-1K-1]
→
The speed of light in air is 3.00 × 108ms-1. The distance travelled by light in one year (i.e., 365 days = 3.154 × 107s) is known as light year. A student calculates one light year = 9.462 × 1015m. Do you agree with the student? If not, write the correct value of one light year.
→
According to the molecular kinetic theory of gases, what is the mean free path?
→
The volume of an ideal gas is V at a pressure P. On increasing the pressure by $\Delta\text{P},$ the change in volume of the gas is $(\Delta\text{V}_1)$ under isothermal conditions and $(\Delta\text{V}_2)$ under adiabatic conditions. Is $\Delta\text{V}_1>\Delta\text{V}_2$ or vice-versa and why?
→
A Carnot engine whose heat sink is at 27°C has an efficiency of 40%. By how many degrees should the temperature of source be changed to increase the efficiency by 10% of the original efficiency?
→
Two charged particles, having equal charges of 2.0 × 10-5C each, are brought from infinity to within a separation of 10cm. Find the increase in the electric potential energy during the process.
→
Some measurements are taken for the period of oscillations of a simple pendulum. In successive measurements, the readings turn out to be 2.63s, 2.56s, 2.42s, 2.71s and 2.80s. Calculate the absolute errors, relative error and percentage error.
→
Four identical hollow cylindrical columns of mild steel support a big structure of mass 50,000kg. The inner and outer radii of each column are 30 and 60cm respectively. Assuming the load distribution to be uniform, calculate the compressional strain of each column.
→