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Sound Waves: Open Tube

Q- The fundamental frequency of an open-open tube is 1500 Hz, when it is filled with helium at 0oC. What is the frequency when it is field with air at 0oC?

Solution:

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Conservation of energy

Q- An object of mass m starts from rest and slides a distance d down a frictionless incline of angle θ. While sliding, it contacts an unstressed spring of negligible massand force constant k.  The object slides an additional distance x as it is brought momentarily to rest by compression of the spr…

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Heat and Thermodynamics

Q- 0.110 mol of a monatomic gas follows the process shown in the figure.

(a) How much heat energy is transferred to or from the gas during process 1 → 2 ?

(b) How much heat energy is transferred to or from the gas during process 2 → 3?

(c) What is the total change in thermal energy of the ga…

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Ray Optics: Achromatic Lens

Q- An achromatic doublet consists of a biconvex positive lens of refractive index μ1 in contact with a plano concave lens of refractive index μ2. All curved surfaces have a radius of curvature R = 25 cm.

(a) If μ1red = 1.49 what is the focal length of the biconvex lens for red light?

(b) If μ2…

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Circular Motion

A 1.9 kg ball is attached to the lower end of a length of fishline with a breaking strength of 35 N. The top end of the fishing line is held stationary. The ball is released from rest with the line taut and horizontal. At what angle  (measured from the vertical) will the fishline break?

Solution:

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D C Circuits

Q- Consider the circuit in the figure. The switch is closed for long time prior to t = 0.

(a) Determine the voltage Vc across the capacitor before t = 0 and long time after t = 0

(b) Find the  expression for the voltage across the capacitor as a function of time

(c) Determine the time constant a…

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Rotetional Motion

Q- A thin rod is held vertically with its lower end resting on a frictionless horizontal surface. The rod is then released to fall freely.

(a) Determine the speed of its center of mass just before it hits the horizontal surface. Use h, M, and g for length, mass, and gravitational acceleration res…

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Linear Motion Combined with Rotaional Motion

Q- A m1 = 16.0 kg object and a m2 = 12.5 kg object are suspended, joined by a cord that passes over a pulley with a radius of 10.0 cm and a mass of 3.00 kg. The cord has a negligible mass and does not slip on the pulley. The pulley rotates on its axis without friction. The objects start from rest 3.…

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EMI: Induced Current

Q-Two parallel circular loops of wire having the same common axis.  The smaller loop of radius r, and is above the larger loop (radius R) by a distance X>>R.  the magnetic field due to the counterclockwise current i in the larger loop is nearly uniform throughout the smaller loop.  Suppose that x is…

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Circular Motion

(Requested by Tricky Bits)

Q- A wheel 1.9 m in diameter lies in a vertical plane and rotates about its central axis with a constant angular acceleration of 4.15 rad/s2. The wheel starts from rest at t = 0, and the radius vector of a certain point P on the rim makes an angle of 57.3o with the hori…

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Conservation of Energy: Motion in Vertical Plane

Q- A pendulum consists of a string of length L and a bob of mass M.  The string is brought to a horizontal position and given the minimum initial speed enabling a pendulum to make a full turn in the vertical plane.  

a) what is the maximum kinetic energy K of the bob? 

b) what is the tension …

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Electrostatics: Capacitance

Q- Five 1 inch square plates are arranged as shown in figure. The plate spacings are 0.01 inch. The arrangement is to be used for a displacement transducer by observing the change in capacitance with the distance x. Calculate the sensitivity of the device in picofarads per inch. Assume that the plat…

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Differentiation

Q- At a sand and gravel plant, sand is falling off a conveyor and onto a conical pile at a rate of 10 cubic feet per minute.  The diameter of the base of the cone is 3 times the altitude.  At what rate is the height of the pile changing when the pile is 15 feet high?

Solution:

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Magnetic Force

Q- A rectangular coil of wire, 22.0 cm by 35.0 cm and carrying a current 1.40 A, is oriented with the plane of its loop perpendicular to a uniform 1.50 T magnetic field in to the plane of the coil.

a) Calculate the net force and torque which the magnetic field exerts on the coil.

b) The coil is ro…

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Refraction Through A Prism

Q- A horizontal beam of light that is incident on an equilateral prism. The base of the prism is horizontal. The prism (n = 1.40) is surrounded by a liquid whose index of refraction is 1.60. Determine the angle of emergence from the other surface, that is the exiting light makes with the normal to t…

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Sound and Vibration

Q- A heavy piece of hanging sculpture is suspended by a 90 cm long, 5.0 g steel wire. When the wind blows hard, the wire hums at its fundamental frequency of 80 Hz. What is the mass of the sculpture?

Solution:

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Mechanics: Conservation of momentum

Q- Two railroad cars moving on same track towards each other. One of mass 10000 kg with speed 0.3 m/s and the other of mass 15000 kg with speed of 0.1 m/s.

(a) What is the magnitude of their common velocity after they coule together?

(b) How much kinetic energy is lost during collision?   

So…

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Thermodynamics: Specific Heat Capacity

Q- A well-sealed room contains 80 kg of air at 200 kPa and 25°C. Now solar energy enters the room from windows at an average rate of 1 kJ/s while a 100-W fan is turned on to circulate the air in the room. If heat transfer through the walls is negligible, what will be the air temperature in the room …

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Rotation: Toppling

Q- I have a 1.5 m tall air compressor that weights 50 kg with a 0.5 m square base. I have a cart that is 1m x 2m. The surface of the cart where the compressor will be mounted is 0.25 m off the ground. The cart wheels are in the corners, it is rated to carry 500 kg and weighs 75 kg. If the compressor…

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Electrostatics: Induced Charges

Q- A point charge q is placed between two infinitely large conducting parallel planes with distance d between them, such that it is at a distance x from one plane.  Find the charges induced on each plane.

Solution:

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