Download App

Rotational Dynamics — Physics STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 SciencePhysicsRotational Dynamics2 Marks
Question
Certain stars are believed to be rotating at about $1 \mathrm{rot} / \mathrm{s}$. If such a star has a diameter of 40 $\mathrm{km}$, what is the linear speed of a point on the equator of the star?
✓

Answer

$
\begin{aligned}
& \text { Data : } \mathrm{d}=40 \mathrm{~km}, /=1 \mathrm{rot} / \mathrm{s} \\
& \therefore \mathrm{r}=\frac{d}{2}=\frac{40 \mathrm{~km}}{2}=20 \mathrm{~km}=2 \times 10^4 \mathrm{~m}
\end{aligned}
$
Linear speed, $v=\omega \mathrm{r}=(2 \pi f) r$
$
\begin{aligned}
& =(2 \times 3.142 \times 1)\left(2 \times 10^4\right) \\
& =6.284 \times 2 \times 10^4 \\
& \left.=1.257 \times 10^5 \mathrm{~m} / \mathrm{s} \text { (or } 125.6 \mathrm{~km} / \mathrm{s}\right)
\end{aligned}
$

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 "Short Answer Type Question" from Rotational Dynamics→Rotational Dynamics — all question types→Physics STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

Show that the orbital magnetic dipole moment of a revolving electron is $\frac{ evr }{2}$
→
What is an extensive variable? Give examples.
→
Give one example of uniform circular motion.
→
A Plane Wavefront of light of wavelength 5500 A.U. is incident on two slits in a screen perpendicular to the direction of light rays. If the total separation of 10 bright fringes on a screen 2 m away is 2 cm. Find the distance between the slits.
→
A particle performs UCM. The diameter of the circle is $4 cm$. What is the amplitude of linear SHM that is the projection of the UCM on a diameter?
→
When a gas is heated its temperature increases. Explain this phenomenon based on kinetic theory of gases.
→
Find the amplitude of the resultant wave produced due to interference of two waves given as $y_1 = A_1 \sin \omega t y_2 = A_2 \sin (\omega t + φ)$
→
Obtain the relation between the magnitude of linear acceleration and angular acceleration in circular motion.
→
State any two conditions for steady interference pattern
→
Starting with $r=\frac{\varepsilon_0 h^2 n^2}{\pi m Z e^2}$, Show that the speed of an electron in $n ^{\text {th }}$ orbit varies inversely to principal quantum number.
→