Download App

Work, Energy, and Power — Physics STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 SciencePhysicsWork, Energy, and Power3 Marks
Question
A simple pendulum consists of a 50cm long string connected to a 100g ball. The ball is pulled aside so that the string makes an angle of 37° with the vertical and is then released. Find the tension in the string when the bob is at its lowest position.
✓

Answer

From the figure, $\cos\theta=\frac{\text{AC}}{\text{AB}}$
$\Rightarrow\text{AC}=\text{AB}\cos\theta$ $\Rightarrow(0.5)\times(0.8)=0.4$ So, CD = (0.5) - (0.4) = (0.1)m Energy at D = energy at B $\frac{1}{2}\text{mv}^2=\text{mg}(\text{CD})$ $\text{v}^2=2\times10\times(0.1)=2$ So, the tension is given by, $\text{T}=\frac{\text{mv}^2}{\text{r}}+\text{mg}$ $\Rightarrow(0.1)\Big(\frac{2}{0.5}+10\Big)=1.4\text{N}$

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 Work, Energy, and Power→Work, Energy, and Power — all question types→Physics STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

An object P is focused by a microscope M. A glass slab of thickness 2.1cm is introduced between P and M. If the refractive index of the slab is 1.5, by what distance should the microscope be shifted to focus the object again?
→
Three objects of equal mass $M$ are located at the vertices of an equilateral triangle of side $a$. At what speed should the three bodies be rotated on a circle so that the triangle moves on the circumference of the circular chamber and the side of the triangle remains unchanged.
→
Absolute zero temperature is not the temperature of zero energy. Explain.
→
Show that vectors $\text{A}=2\hat{\text{i}}-3\hat{\text{j}}-\hat{\text{k}}$ and $\text{B}=-6\hat{\text{i}}+9\hat{\text{j}}+3\hat{\text{k}}$
are parallel.
→
A bulb rated 60W at 220V is connected across a household supply of alternating voltage of 220V. Calculate the maximum instantaneous current through the filament.
→
A proton describes a circle of radius 1cm in a magnetic field of strength 0.10T. What would be the radius of the circle described by an α-particle moving with the same speed in the same magnetic field?
→
Define standing wave. Displacement of a string in which standing wave is formed is given as $\text{y}=(20\sin157\text{x}\cos314\text{t})$ Find:
  1. Amplitude of individual waves.
  2. Velocity of wave.
→
Derive an expression for the potential energy of an elastic stretched spring.
→
An inductor-coil, a capacitor and an AC source of rms voltage 24V are connected in series. When the frequency of the source is varied, a maximum rms current of 6.0A is observed. If this inductor coil is connected to a battery of emf 12V and internal resistance $4.0\Omega,$ what will be the current?
→
In the original Fizeau method, the light travelled 8.6km and then returned. What could be the difficulty if this distance is taken as 8.6m?
→