(English Medium) ICSE Class 9 - CISCE Question Bank Solutions

A small stone of mass m ( = 200 g ) is held underwater in a tall jar and allowed to fall as shown in the following figure. The free-body diagram of the stone is also shown.

(i) What does F₂ represent?

(ii) What does m₁ represent?

(iii) What is the net force acting on the stone?

(iv) What is the acceleration of the stone as it falls through water? Neglect the force due to viscosity. Assume that volume of stone = 80 cml, density of water = 1.0 g cm^-3 and acceleration due to gravity g = 10 ms^-2.

Write the SI units of Buoyant force

What do you mean by buoyancy?

What is meant by up thrust?

Is pressure a vector quantity?

Is thrust a scalar or vector quantity?

How is thrust different from pressure?

Define atmospheric pressure diving suits. Does a diving suit create buoyancy?

Sound is a ______ wave and needs a material medium to travel.

What are magnetic and non-magnetic substances? Give two examples of each.

Which of the quantity-speed or velocity-gives the direction of motion of a body?

Calculate the pressure exerted by 0.8 m vertical length of alcohol of density 0.80 gcnr⁵ in SI units.
[Take g = 10 ms⁻²].

What is the pressure exerted by 75 cm vertical column of mercury of density 13600 kgm⁻³ in SI units?
[Take g = 9.8 ms⁻²].

What vertical height of water will exert a pressure of 333200 Pa? The density of water is 1000 kgnr³ and g = 9.8 ms⁻².

Pressure at the bottom of the sea at some particular place is 8968960 Pa. If the density of seawater is 1040 kgm³ calculate the depth of the sea. Take g = 9.8 ms⁻². Neglect the pressure of the atmosphere.

Calculate the equivalent height of mercury, which will exert as much pressure as 960 m of seawater of density 1040 kgm⁻³. The density of mercury is 13600 kgm⁻³.

The pressure of water on the ground floor, in a water pipe is 150000 Pa, whereas pressure on the fourth floor is 30000 Pa. Calculate the height of the fourth floor. Take g = 10 ms⁻².

The pressure of water on the ground floor is 160000 Pa. Calculate the pressure on the fifth floor, at a height of 15 m.

The normal pressure of air is 76 cm of mercury. Calculate the pressure in SI units.
[Density of mercury = 13600 kg/m³ and g = 10 m/s²]