MCQ
The time period of a simple pendulum measured inside a stationary lift is found to be $T$. If the lift starts accelerating upwards with an acceleration $g/3$, the time period is
- A$T\sqrt 3 $
- ✓$T\sqrt 3 /2$
- C$T/\sqrt 3 $
- D$T/3$
✓
Answer
Correct option: B.
$T\sqrt 3 /2$
b
(b) $T = 2\pi \sqrt {\frac{l}{g}} $ and $T' = 2\pi \sqrt {\frac{l}{{4g/3}}} $
(b) $T = 2\pi \sqrt {\frac{l}{g}} $ and $T' = 2\pi \sqrt {\frac{l}{{4g/3}}} $
$[As\;g' = g + a = g + \frac{g}{3} = \frac{{4g}}{3}$]
$T' = \frac{{\sqrt 3 }}{2}T$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A second's pendulum is placed in a space laboratory orbiting around the earth at a height $3R$, where $R$ is the radius of the earth. The time period of the pendulum is
→A ball of mass $200\,g$ rests on a vertical post of height $20\,m$. A bullet of mass $10\,g$, travelling in horizontal direction, hits the centre of the ball. After collision both travels independently. The ball hits the ground at a distance $30\,m$ and the bullet at a distance of $120\,m$ from the foot of the post. The value of initial velocity of the bullet will be $............m/s$ (if $\left.g =10 m / s ^2\right)$
→A Carnot engine whose sink is at $300\, K$ has an efficiency of $40\%.$ By how much should the temperature of source be increased so as to increase its efficiency by $50\%$ of original efficiency ..... $K$
→A mass $M$ is supported by a mass less string would wound a uniform cylinder of mass $M$ and radius $R$. On releasing the mass from rest, it will fall with acceleration
→A man is crossing a river flowing with velocity of $5\,\, m/s$. He reaches a point directly across at a distance of $60\,\, m$ in $5 \,\,sec$. His velocity in still water should be ........ $m/s$
→Solar radiation emitted by sun resembles that emitted by a black body at a temperature of $6000 K$ . Maximum intensity is emitted at a wavelength of about $4800Å$ . If the sun were to cool down from $6000 K$ to $3000 K$ then the peak intensity would occur at a wavelength ....... $\overset{o}{\mathop{A}}\,$
→Find maximum amplitude for safe $SHM$ (block does not topple during $SHM$) of $a$ cubical block of side $'a'$ on a smooth horizontal floor as shown in figure (spring is massless)
→The maximum horizontal range of a projectile is $16\,km$ when the projectile is thrown at an elevation of $30^o$ from the horizontal, it will reach to the maximum height of ....... $km$
→It is found that if a neutron suffers an elastic collinear collision with deuterium at rest, fractional loss of its energy is $p_d $ ; while for its similar collision with carbon nucleus at rest, fractional loss of energy is $P_c$. The values of $P_d$ and $P_c$ are respectively
→A particle is projected from a horizontal plane ($x-z$ plane) such that its velocity vector at time t is given by $\vec V = a\hat i + (b - ct)\hat j$ Its range on the horizontal plane is given by
→