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(a) Which physical quantities are represented by the (i) Rate of change of angular momentum (ii) Product of I and `vecw`(b) Show that angular momentum of a satellite of mass MS revolving around the earth having mass Me in an orbit of radius r is equal to `[G Me

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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(a) A cat is able to land on its feet after a fall. Why?(b) If angular momentum moment of inertia is decreased, will its rotational K E. . be also conserved?

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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(a) Why is moment of inertia called rotational inertia? (b) Calculate M.I of a uniform circular disc of mass 500gm and radius 10cm about (i) Diameter (ii) axis tangent to the disc and parallel to diameter (c) Axis passing trough centre and perpendicular to its

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Define Gravitational potential energy Hence deduces an expression for gravitational potential energy of a body placed at a point sear the surface of

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State the principle on which Hydraulic lift work and explain its

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What is Bernoulli’s theorem? Show that sum of pressure, potential and kinetic energy in the streamline flow is

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Derive an expression for the work done during isothermal

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Briefly describe a Carnot cycle and derive an expression for the efficiency of Carnot

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Derive an expression for the pressure due to an ideal

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A solid sphere rolls down two different inclined planes of the same heights but different angles of inclination. (a) Will it reach the bottom with the same speed in each case? (b) Will it take longer to roll down one plane than the other? (c) If so, which one and

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A hoop of radius 2 m weighs 100 kg. It rolls along a horizontal floor so that its centre of mass has a speed of 20 cm/s. How much work has to be done to stop

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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The oxygen molecule has a mass of `5.30 × 10^(-26)` kg and a moment of inertia of `1.94×10^(-46)` kg `m^2` about an axis through its centre perpendicular to the lines joining the two atoms. Suppose the mean speed of such a molecule in a gas is 500 m/s and that its kinetic energy of rotation is two thirds of its kinetic energy of translation. Find the average angular velocity of the

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A solid cylinder rolls up an inclined plane of angle of inclination 30°. At the bottom of the inclined plane the centre of mass of the cylinder has a speed of 5 m/s. (a) How far will the cylinder go up the plane? (b) How long will it take to return to the

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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As shown in Fig., the two sides of a step ladder BA and CA are 1.6 m long and hinged at A. A rope DE, 0.5 m is tied half way up. A weight 40 kg is suspended from a point F, 1.2 m from B along the ladder BA. Assuming the floor to be friction-less and neglecting the weight of the ladder, find the tension in the rope and forces exerted by the floor on the ladder. (Take g = 9.8 m/`s^2`) (Hint: Consider the equilibrium of each side of the ladder separately.)

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A man stands on a rotating platform, with his arms stretched horizontally holding a 5 kg weight in each hand. The angular speed of the platform is 30 revolutions per minute. The man then brings his arms close to his body with the distance of each weight from the axis changing from 90cm to 20cm. The moment of inertia of the man together with the platform may be taken to be constant and equal to 7.6 kg `m^2`. (a) What is his new angular speed? (Neglect friction.) (b) Is kinetic energy conserved in the process? If not, from where does

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A bullet of mass 10 g and speed 500 m/s is fired into a door and gets embedded exactly at the centre of the door. The door is 1.0 m wide and weighs 12 kg. It is hinged at one end and rotates about a vertical axis practically without friction. Find the angular speed of the door just after the bullet embeds into it. (Hint: The moment of inertia of the door about the vertical axis at one end is

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Two discs of moments of inertia `I_1` and `I_2` about their respective axes (normal to the disc and passing through the centre), and rotating with angular speeds `ω_1` and `ω_2` are brought into contact face to face with their axes of rotation coincident. (a) What is the angular speed of the two-disc system? (b) Show that the kinetic energy of the combined system is less than the sum of the initial kinetic energies of the two discs. How do you account for this loss in energy? Take `ω_1` ≠

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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(a) Prove the theorem of perpendicular axes. (Hint : Square of the distance of a point (x, y) in the x–y plane from an axis through the origin and perpendicular to the plane is `x^2+y^2`). (b) Prove the theorem of parallel axes. (Hint : If the centre of mass is chosen to be the origin `m_ir_i = 0`

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Prove the result that the velocity v of translation of a rolling body (like a ring, disc, cylinder or sphere) at the bottom of an inclined plane of a height h is given by `v^2=(2gh)/(1+k^2/R^2)` using dynamical consideration (i.e. by consideration of forces and torques). Note k is the radius of gyration of the body about its symmetry axis, and R is the radius of the body. The body starts from rest at the top of the

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A disc rotating about its axis with angular speed `ω_o` is placed lightly (without any translational push) on a perfectly frictionless table. The radius of the disc is R. What are the linear velocities of the points A, B and C on the disc shown in Fig. ? Will the disc roll in the direction indicated ?

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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