Search & Filtering
a rod of length l varies linearly with position along its length, such that it increas to thrice its value from one end to the other. this rod is paleced on a frictionless horizontal surface and a horizontal force of magnitude f is applied to a point on the rod. at what point should this force be applied such that the rod slides on the surface without rotating
A cylindrical region of space of radius R, defined as x^2 + y^2 < R^2, is filled with a homogeneous magnetic field of strength B, parallel to the z-axis; there is no magnetic field elsewhere. A particle of mass m and charge e moves with velocity v, parallel to the x-axis, and enters the magnetic field at x = −R, y = 0. Determine the angle between the x-axis and the velocity vector of the particle after it has left the magnetic field.
Calculate the root mean square velocity of air molecules at N.T.P.(Density of air = 1.293 Kg/m³).
What is the maximum deceleration that a car with anti-lock brakes can achieve on horizontal wet asphalt when the coefficient of sliding friction between the road and the tire is 0.50 and the coefficient of rest friction is 0.60?
An engine is tested by means of a water brake at 1000 rpm. The measured torque of the engine is 10000 Nm and the water consumption of the brake is 0.5 m3 /s, its inlet temperature being 20°C.
Calculate the water temperature at exit, assuming that the whole of the engine power is ultimately transformed into heat which is absorbed by the cooling water.
Rigid tank contains a hot fluid that is cooled while being stirred by a paddle wheel. Initially, the internal energy of the fluid is 800 kJ. During the cooling process, the fluid loses 500 kJ of heat, and the paddle wheel does 100 kJ of work on the fluid. Determine the final internal energy of the fluid. Neglect the energy stored in the paddle wheel.
A 3kW electric kettle is filled with water at 15°C and switched on,it then takes 2 minutes to come to the boil.
A body is projected at an angle of 53°, with the horizontal ,with velocity of 30m/s. What the angle(direction) of velocity vector is as measured from horizontal , when the projectile at it's maximum point on it's trajectory ?
obtain two different factors of physical quantity "pressure" in two different systems of unit
1 Consider a vessel with a diameter of T=0.9 m, and a ratio of the propeller diameter to vessel diameter equal to 0.37. Consider the height of the vessel H-T. The working fluid has a density of 1100 kg/m and dynamic viscosity 0.022 Pas. Determine:
(a) The rotation frequency N (in rpm) needed to reach a Reynolds number of 10
(b) The power in kW) corresponding to the frequency computed in point (a) and to a power number of 2.5
(c) The specific mean dissipation rate as well as the Kolmogorov length scale
3 marks
3 marks
3 marks
(d) By reference to figure I, at a Reynolds number of 10, which types of impeller should we 3 marks use for the power number to be in the range 2.5 - 3? Also, which impeller would you chose to maximise the power number at the same Reynolds number?
(c) If we are to further increase the power number beyond the maximum value observed in 2 marks figure 1 for the same type of impeller and diameter, which modification would you need to provide to the impeller?
(f) Assume we want now to scale up the vessel by a factor of 15. maintaining a similar 6 marks geometry, to match conditions in a plant. Determine the power requirement in the plant in order to have a similar mixing time with respect to the lab scale vessel, for which the power was computed in point (b), and assuming the same frequency N computed in point (a). Also, compute the Reynolds number corresponding to the plant vessel.
(g)
If we need to decrease the power with respect to the value computed in point (1) by 10%, 5 marks how much the frequency N will need to vary in order to have the same power number?
***
Pewer ons lar ume typical impallers, hem Hamrajani A Tarternan (0
11) de Rei CDT) WD1% S etubade e FTWD 1/3 Dio hade disk flat hade turtine m wD-in 14 hade la ballade rhine FHT) WD-N, which eine (T) WD
iNs hinde treat eare impeller WD-
Figure Q1
