Advertisements
Advertisements
प्रश्न
A cubical block of wood weighing 200 g has a lead piece fastened underneath. Find the mass of the lead piece which will just allow the block to float in water. Specific gravity of wood is 0.8 and that of lead is 11.3.
Advertisements
उत्तर
Given:
Density of wood, ρw = 0.8 gm/cc
Density of lead, ρpb = 11.3 gm/cc
Weight of the cubical wood block, mw = 200 g
The cubical block floats in water.
Now,
(mw+ mpb) × g = (Vw + Vpb)ρ × g
Here,
ρ = Density of water
Vw = Volume of wood
Vpb = Volume of lead
\[\Rightarrow ( \text{m}_\text{w} + \text{m}_{\text{pb}} ) = \left( \frac{\text{m}_\text{w}}{\rho_\text{w}} + \frac{\text{ m}_{\text{pb}}}{\rho_{\text{pb}}} \right)\rho\]
\[ \Rightarrow (200 + \text{m}_{\text{pb}} ) = \left( \frac{200}{0 . 8} + \frac{\text{m}_{\text{pb}}}{11 . 3} \right) \times 1\]
\[ \Rightarrow \text{m}_{\text{pb}} - \frac{\text{m}_{\text{pb}}}{11 . 3} = 250 - 200\]
\[ \Rightarrow \frac{10 . 3 \text{m}_{\text{pb}}}{11 . 3} = 50\]
\[ \Rightarrow \text{m}_{\text{pb}} = \frac{50 \times 11 . 3}{10 . 3} = 54 . 8 \text{ gm }\]
APPEARS IN
संबंधित प्रश्न
Explain why The angle of contact of mercury with glass is obtuse, while that of water with glass is acute
A U-shaped wire is dipped in a soap solution and removed. The thin soap film formed between the wire and the light slider supports a weight of 1.5 × 10–2 N (which includes the small weight of the slider). The length of the slider is 30 cm. What is the surface tension of the film?
Figure (a) shows a thin liquid film supporting a small weight = 4.5 × 10–2 N. What is the weight supported by a film of the same liquid at the same temperature in Fig. (b) and (c)? Explain your answer physically.
It is said that a liquid rises or is depressed in capillary due to the surface tension. If a liquid neither rises nor depresses in a capillary, can we conclude that the surface tension of the liquid is zero?
If water in one flask and castor oil in other are violently shaken and kept on a table, which will come to rest earlier?
By a surface of a liquid we mean
If more air is pushed in a soap bubble, the pressure in it
The rise of a liquid in a capillary tube depends on
(a) the material
(b) the length
(c) the outer radius
(d) the inner radius of the tube
Consider an ice cube of edge 1.0 cm kept in a gravity-free hall. Find the surface area of the water when the ice melts. Neglect the difference in densities of ice and water.
A wire forming a loop is dipped into soap solution and taken out so that a film of soap solution is formed. A loop of 6.28 cm long thread is gently put on the film and the film is pricked with a needle inside the loop. The thread loop takes the shape of a circle. Find the tension the the thread. Surface tension of soap solution = 0.030 N m−1.
A cubical box is to be constructed with iron sheets 1 mm in thickness. What can be the minimum value of the external edge so that the cube does not sink in water? Density of iron = 8000 kg/m3 and density of water = 1000 kg/m3.
How much amount of work is done in forming a soap bubble of radius r?
Water rises to a height of 20 mm in a capillary tube. If the radius made 1/3rd of its previous value, to what height will the water now rise in the tube?
A square frame of each side L is dipped in a soap solution and taken out. The force acting on the film formed is _____.
(T = surface tension of soap solution).
The sap in trees, which consists mainly of water in summer, rises in a system of capillaries of radius r = 2.5 × 10–5 m. The surface tension of sap is T = 7.28 × 10–2 Nm–1 and the angle of contact is 0°. Does surface tension alone account for the supply of water to the top of all trees?
Two narrow bores of diameter 5.0 mm and 8.0 mm are joined together to form a U-shaped tube open at both ends. If this U-tube contains water, what is the difference in the level of the two limbs, of the tube?
[Take surface tension of water T = 7.3 × 10-2 Nm-1, angle of contact = 0, g = 10 ms-2 and density of water = 1.0 × 103 kgm-3]
The surface tension of soap solution is 25 × 10-3 Nm-1. The excess of pressure inside a soap bubble of diameter 1 cm is ______.
The surface tension of boiling water is ______.
A drop of water of radius 8 mm breaks into number of droplets each of radius 1 mm. How many droplets will be formed?
