MCQ
On a planet a freely falling body takes $2 \,sec$ when it is dropped from a height of $8 \,m$, the time period of simple pendulum of length $1\, m$ on that planet is ..... $\sec$
- ✓$3.14 $
- B$16.28$
- C$1.57$
- DNone of these
✓
Answer
Correct option: A.
$3.14 $
a
(a) On a planet, if a body dropped initial velocity $(u = 0)$ from a height h and takes time t to reach the ground then $h = \frac{1}{2}{g_P}{t^2}$
(a) On a planet, if a body dropped initial velocity $(u = 0)$ from a height h and takes time t to reach the ground then $h = \frac{1}{2}{g_P}{t^2}$
$ \Rightarrow {g_P} = \frac{{2\,h}}{{{t^2}}} = \frac{{2 \times 8}}{4} = 4\,m/{s^2}$
Using $T = 2\pi \sqrt {\frac{l}{g}} $ ==> $T = 2\,\pi \sqrt {\frac{1}{4}} = \pi = 3.14\,$sec.
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
Moment of inertia of a uniform circular disc about a diameter is $I$. Its moment of inertia about an axis perpendicular to its plane and passing through a point on its rim will be
→A $U-$ tube containing a liquid moves with a horizontal acceleration a along a direction joining the two vertical limbs. The separation between these limbs is $d$ . The difference in their liquid levels is
→A bucket contains water filled upto a height $=$ $15 cm$. The bucket is tied to a rope which is passed over a frictionless light pulley and the other end of the rope is tied to a weight of mass which is half of that of the (bucket $+$ water). The water pressure above atmosphere pressure at the bottom is ....... $kPa$
→A thief stole a box full of valuable articles of weight $W$ and while carrying it on his back, he jumped down a wall of height $ ‘h’$ from the ground. Before he reached the ground he experienced a load of
→At what angle of elevation, should a projectile be projected with velocity $20 \,ms ^{-1}$, so as to reach a maximum height of $10 \,m$ ?
→A force of $6\; N$ acts on a body at rest and of mass $1\; kg$. During this time, the body attains a velocity of $30\; m / s$. The time for which the force acts on the body is ..... $seconds$
→A body is projected vertically upwards from the surface of a planet of radius $R$ with a velocity equal to half the escape velocity for that planet. The maximum height attained by the body is
→A ball is held in the position shown with string of length $1\,\, m$ just taut & then projected horizontally with a velocity of $3 \,\,m/s$. If the string becomes taut again when it is vertical, angle $\theta$ is given by ........ $^o$
→A spring of force constant $k$ is cut into lengths of ratio $1:2:3$ . They are connected in series and the new force constant is $k'$ . Then they are connected in parallel and force constant is $k''$ . Then $k':k''$ is
→A point particle is held on the axis of a ring of mass $m$ and radius $r$ at a distance $r$ from its centre $C$. When released, it reaches $C$ under the gravitational attraction of the ring. Its speed at $C$ will be
→