Question
In a hydraulic lift, the input piston has surface area $20 \mathrm{~cm}^2$. The output piston has surface area $1000 \mathrm{~cm}^2$. If a force of $50 \mathrm{~N}$ is applied to the input piston, it raises the output piston by $2 \mathrm{~m}$. Calculate the weight of the support on the output piston and the work done by it.

Answer


$
\begin{aligned}
& \text { Data: } A_1=20 \mathrm{~cm}^2=2 \times 10^{-3} \mathrm{~m}^2, \\
& A_2=1000 \mathrm{~cm}^2=10^{-1} \mathrm{~m}^2, F_1=50 \mathrm{~N}, \mathrm{~s}_2=2 \mathrm{~m}
\end{aligned}
$
(i) By Pascal's law,
$
\begin{aligned}
& \frac{F_1}{A_1}=\frac{F_2}{A_2} \\
& \therefore F_2=F_1 \frac{A_2}{A_1} \\
& =(50 \mathrm{~N}) \times \frac{10^{-1} \mathrm{~m}^2}{2 \times 10^{-3} \mathrm{~m}^2}=50 \times 50 \\
& =2500 \mathrm{~N} \\
&
\end{aligned}
$
This gives the weight of the support on the output piston.
(ii) The work done by the force transmitted to the output piston is
$
\begin{aligned}
& \mathrm{F}_2 \mathrm{~S}_2=(2500 \mathrm{~N})(2 \mathrm{~m}) \\
& =5000 \mathrm{~J}
\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

Similar questions

A ballet dancer spins about a vertical axis at \(2.5 (\pi\) rad / sec). with his both arms outstretched. With the arms folded, the moment of inertia about the same axis of rotation changes by \(25 \%\). Calculate the new rotation in r.p.m.
What is the resolving power of a telescope if the diameter of the objective of the telescope is $1.22 m$ and the wavelength of light is $5000 \mathring A $ ? .
State the MI of a thin rectangular plate-of mass M, length l and breadth b about its transverse axis passing through its centre. Hence find its MI about a parallel axis through the midpoint of edge of length b.
A horizontal disc is rotating about a transverse axis through its centre at $100 \mathrm{rpm}$. A $20 \mathrm{gram}$ blob of wax falls on the disc and sticks to it at $5 \mathrm{~cm}$ from its axis. The moment of inertia of the disc about its axis passing through its centre is $2 \times 10^{-4} \mathrm{~kg} \cdot \mathrm{m}^2$. Calculate the new frequency of rotation of the disc.
State an expression for the radius of gyration of
(i) a thin ring
(ii) a thin disc, about respective transverse symmetry axis.
OR
Show that for rotation about respective transverse symmetry axis, the radius of gyration of a thin disc is less than that of a thin ring.
A network of four capacitors of \(6 \mu F\) each is connected to a \(240 V\) supply. Determine the charge on each capacitor.
Image
State Ampere's circuital law. Obtain an expression for magnetic induction along the axis of toroid.
A $10 H$ inductor carries a current of $25 A$. Flow much ice at $0{ }^{\circ} C$ could be melted by the energy stored in the magnetic field of the inductor? [Latent heat of fusion of ice, $L_f=335$ $J / g ]$
A metal disc is made to spin at 20 revolutions per second about an axis passing through its centre and normal to its plane. The disc has a radius of 30 cm and spins in a uniform magnetic field of 0.20 T, which is parallel to the axis of rotation. Calculate
(a) The area swept out per second by the radius of the disc,
(b) The flux cut per second by a radius of the disc,
(c) The induced emf in the disc.
If the difference in speeds of light in glass and water is $0.25 \times 10^8\ m / s$, find the speed of light in air. $\left[n_g=1.5\right.$ and $\left.n_w=\frac{4}{3}\right]$