PART - 2 CH - 9 Mechanical Properties of Fluids — Physics STD 11 Science — Question

A particle on a stretched string supporting a travelling wave, takes 5.0ms to move from its mean position to the extreme position. The distance between two consecutive particles, which are at their mean positions, is 2.0cm. Find the frequency, the wavelength and the wave speed.

Find the expression for time period of motion of a body suspended by two springs connected in parallel and series.

A ball of mass 50g moving at a speed of 2.0m/s strikes a plane surface at an angle of incidence 45°. The ball is reflected by the plane at equal angle of reflection with the same speed. Calculate

1. The magnitude of the change in momentum of the ball.
2. The change in the magnitude of the momentum of the ball.

Figure. shows a large closed cylindrical tank containing water. Initially the air trapped above the water surface has a height h₀ and pressure 2p₀ where p₀ is the atmospheric pressure. There is a hole in the wall of the tank at a depth h₁ below the top from which water comes out. A long vertical tube is connected as shown.

1. Find the height h₂ of the water in the long tube above the top initially.
2. Find the speed with which water comes out of the hole.
3. Find the height of the water in the long tube above the top when the water stops coming out of the hole.

Air is pumped into the tubes of a cycle rickshaw at a pressure of 2 atm. The volume of each tube at this pressure is 0.002m³. One of the tubes gets punctured and the volume of the tube reduces to 0.0005m³. How many moles of air have leaked out? Assume that the temperature remains constant at 300K and that the air behaves as an ideal gas.

A steel tape 1m long is correctly calibrated for a temperature of 27.0°C. The length of a steel rod measured by this tape is found to be 63.0cm on a hot day when the temperature is 450°C. What is the actual length of the steel rod on that day? What is the length of the same steel rod on a day when the temperatures 27.0°C? Coefficient of linear expansion of steel = 1.20 × 10^–5 K^–1.

A steel rod 100cm long is clamped at its middle. The fundamental frequency of longitudinal vibrations of the rod are given to be 2.53 kHz. What is the speed of sound in steel?

Differentiate the following:

1. Wave velocity and particle velocity.
2. Harmonics and overtones.

An eye can distinguish between two points of an object if they are separated by more than 0.22mm when the object is placed at 25cm from the eye. The object is now seen by a compound microscope having a 20D objective and 10D eyepiece separated by a distance of 20cm. The final image is formed at 25cm from the eye. What is the minimum separation between two points of the object which can now be distinguished?