Advertisements
Advertisements
Question
A vessel filled with water is kept on a weighing pan and the scale adjusted to zero. A block of mass M and density ρ is suspended by a massless spring of spring constant k. This block is submerged inside into the water in the vessel. What is the reading of the scale?
Advertisements
Solution
As shown in the diagram, A block of mass M and density p is suspended by a massless spring of spring constants k. This block is submerged in the water in the vessel.
The scale is adjusted to zero, therefore, when the block suspended in spring is immersed in water, then the reading of the scale will be equal to the upthrust on the block due to water.
As we submerge the block into the water, a force equal to the weight of the block acts upward in the form of a buoyant force. So, the downward force applied by the block equals to VPwg
V = the water volume which is displaced by the block
Pw = density of water
Mass of block = M = V
`V = M/p`
So, the reading on the weighing scale reads: `M/p.p_wg = p_w/p M g`
Important point: If the scale is not adjusted to zero as said earlier, the reading on the scale will be different. The weight of the vessel and the weight of water is also added to the reading.
APPEARS IN
RELATED QUESTIONS
Explain why Atmospheric pressure at a height of about 6 km decreases to nearly half of its value at the sea level, though the height of the atmosphere is more than 100 km
Toricelli’s barometer used mercury. Pascal duplicated it using French wine of density 984 kg m–3. Determine the height of the wine column for normal atmospheric pressure.
A large He balloon of volume 1425 m3 is used to lift a payload of 400 kg. Assume that the balloon maintains constant radius as it rises. How high does it rise? [Take y0= 8000 m and `rho_"He"`= 0.18 kg m–3].
Pressure is reduced if .................... increases.
A body weighing 5 kgf, placed on a surface of area 0.1 m2, exerts a thrust on the surface equal to
The feet of lizards act like
Why is the bottom part of the foundation of a building made wider?
If someone presses a pointed needle against your skin, you are hurt. But if someone presses a rod against your skin with the same force, you easily tolerate. Explain.
In a hydraulic lift, the input piston had surface area 30 cm2 and the output piston has surface area of 1500 cm2. If a force of 25 N is applied to the input piston, calculate weight/force on output piston.
A chapatti maker is a machine which converts balls of dough into chapatties. What effect of force comes into play in this process?
If the same force is made to act on a larger area, the pressure ______.
At higher altitudes, atmospheric pressure is ______.
What is thrust?
Why do scuba divers wear a special suit while they go into deep sea levels?
Give reasons why:
cutting edges of knives and axes are sharpened.
What is an Artisan aquifer?
It is easy to compress a gas whereas liquids are ______.
The pressure in mines is ______ than the sea level.
Upthrust = weight of the fluid displaced – apparent weight of the object.
What happens when pressure is increased in solids?
