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Simple Harmonic Motion

Q- Two particles executes SHM of same amplitude of 20 cm with same period along the same line and about same equilibrium position. If the maximum distance between them is 20 cm, find their phase difference.

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Projectile Motion

Q- A shall is fired from a hill of height ‘h’ at an angle of 450.  What is the magnitude of its velocity of projection as a function of its horizontal distance covered on ground x, acceleration due to gravity g and height h?

Solution:

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AC Circuits

Q- In an AC circuit the voltage across a resistive component is given by V(t) = 10 + 5 sin (3t). Find

(a) The voltage amplitude

(b) Root mean square voltage across the component Vrms.

Solution:

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Thermodynamics: Refrigerator

Q- A household refrigerator that has a power input of 450W and a COP of 2.5 is to cool 5 large watermelons, 10 kg each, to 10oC. If the melons are initially at 20oC, determine how long it will take for the refrigerator to cool them. The specific heat of melons = 4.2 kJ/(kg.oC)

Solution:

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Work Done by Variable Force

Q- The force verses displacement graph for a variable force acting on a particle during some displacement is given bellow (the thick lines)

(a) Calculate the total work done by this force on the particle.

(b) Which well-known physical device could produce the type of force during the first 10 seco…

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Heat and Thermodynamics

Q- A piston-cylinder device contains N2 gas, initially at 1.5 bar, 200C, 0.05 m3. The gas is now compressed in a polytropic process, PVn = constant, to 4 bar, 1500C. Determine the polytropic exponent ‘n’, the work done on the gas and the heat transfer.

Solution:

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Standing Waves

Q- One of the 63.5 cm long strings of an ordinary guitar is tuned to produce the not B (frequency 245 Hz) when vibrating in its fundamental mode.

(a) find the speed of the transverse wave on this string.

(b) If the tension in the string is doubled, what will be the new fundamental frequency of the…

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Electrostatics: Flux

Q. A point charge Q is on the axis of a short cylinder at its center. The diameter of the cylinder is equal to its length L (Fig.). What is the total flux through the curved sides of the cylinder?

Solution: 

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Rotational Motion

Q- A solid disk of mass M = 1.3 kg and radius R = 25 cm is free to rotate in a vertical plane about a horizontal axis going through its center. The disk is originally at rest. A piece of clay of mass m= 200 gm (consider particle) drops from 2.5 m above the center of the disk and sticks to its edge a…

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Hydrogen (Like) Atom

Q- The first three energy levels of the fictitious element X are E1 = -3.8 eV, E2 = -1.7 eV, and E3 = -1.2 eV. Element X has one electron in the ground state.

(a) What is the ionization energy of element X?

(b) Calculate the (i) shortest and (ii) next-shortest wavelengths observed in the absorpti…

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Ray Optics: Refraction

Q- An opaque container is 15 cm deep. It contains only a single coin. When looking into the container at a viewing angle of 50o relative to the vertical side of the container, you see nothing on the bottom. When the container is filled with water, you see the coin (from the same viewing angle) on th…

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Newton's Laws: Friction

Q- A box of mass M placed on a table is connected to a hanging mass m by a string passing over a frictionless pulley as in the figure. If the box has mass of 1 kg, the coefficient of friction between the box and table surface is 0.3 and the box slides on the table at constant speed, what is the weig…

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Sound: Intensity and Loudness

Q- A loudspeaker emits a power of 100 W and can be considered as appoint source. Find the sound intensity and sound level in dB at a distance of 10 m from the speaker. How close would you have to be to the speaker for the sound level to be at the threshold of pain (120 dB)?  (The threshold of hearin…

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Thermodynamics

Q- 15 kg of air in a piston cylinder device is heated inside the cylinder from 250C to 750C by passing current through a resistance heater inside the cylinder. The pressure inside the cylinder is kept constant at 2 bar during the process and the heat loss of 50 kJ occurs. Determine the electrical en…

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LR Circuit

Q- The switch for the network of Figure has been closed for long time. It is then opened at the time defined as t = 0 s

(a) Determine the time required for the current Ito drop to 1 mA.

(b) Find the voltage Vat t = 1 ms.

(c) Calculate at t = 5 τ (time constant).

Solution:

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Kirchoff's Law: Mesh Analysis

Q- Using mesh analysis determine the current through 5Ώ resistor and voltage V in the given network.

Solution:

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Ray Optics

Q- A beam of light with red and blue components of wavelengths 670 nm and 425 nm, respectively, strikes a slab of fused quartz at an incident angle of 30o. On refraction, the different components are separated by an angle of 1.31 X 10-3 rad. If the index of refraction of the red light is 1.4925, wh…

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SHM: Damped Oscillation

Q- A 1.5 kg piston supported on a helical spring vibrates freely with a natural frequency of 3Hz. When oscillating within an oil filled cylinder the frequency of free oscillation is reduced to 2.90Hz.

(a) Find the stiffness of the helical spring.

(b) Find the damping ratio when in the oil filled …

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Sound: Resonance

Q- A closed end organ pipe is sounded near a guitar causing one of the strings to vibrate with large amplitude. The string is 80% as long as the organ pipe. If both vibrate at their fundamental frequency, calculate the ratio of the speed of wave on the string to the speed of sound in air.

Solution…

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Thermal Radiation

Q- At high noon, the sun delivers 1000 W to each square meter of a blacktop road. If the hot asphalt loses energy only by radiation, what is its steady-state temperature?

Solution:

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