Q: A copper rod of length $$1\ \mathrm{m} is $$heated from $$20^{\circ}$$\mathrm{C}$$ to 120$$^{\circ}$$\mathrm{C}. If $$the coefficient of linear expansion for copper is $$1.7 \times 10$$^{-5}$$\ \mathrm{K}^{-1}$$, what is the increase in length of the rod?

$$1.7 \times 10$$^{-3}$$\ \mathrm{m}$$

Question 1

A sound wave travels through air at a speed of $$340\ \mathrm{m/s}. If $$the frequency of the wave is $$1700\ \mathrm{Hz}$$, what is the wavelength of the sound wave?

Accepted Answer

$$0.2\ \mathrm{m}$$

Question 2

Which of the following statements best describes the Second Law of Thermodynamics?

Accepted Answer

The entropy of an isolated system never decreases; it either increases or remains constant.

Question 3

A Carnot engine operates between a hot reservoir at $$500\ \mathrm{K}$$ and a cold reservoir at $$300\ \mathrm{K}. $$What is the maximum possible efficiency of this engine?

Accepted Answer

$$0.4$$

Question 4

A $$2\ \mathrm{kg}$$ block is attached to a spring with a force constant $$k = 200\ \mathrm{N/m}. $$What is the period of oscillation for this mass-spring system?

Accepted Answer

$$0.63\ \mathrm{s}$$

Question 5

Which of the following best explains why metals are good conductors of heat?

Accepted Answer

Metals have free electrons that transfer energy rapidly through the lattice.

Question 6

A $$10\ \mathrm{kg}$$ object is dropped from a height of $$20\ \mathrm{m}. $$Ignoring air resistance, what is the speed of the object just before it hits the ground?

Accepted Answer

$$20\ \mathrm{m/s}$$

Question 7

Which of the following is a correct statement about standing waves?

Accepted Answer

Standing waves are formed by the superposition of two waves traveling in opposite directions with the same frequency and amplitude.

Question 8

A copper rod of length $$1\ \mathrm{m} is $$heated from $$20^{\circ}$$\mathrm{C}$$ to 120$$^{\circ}$$\mathrm{C}. If $$the coefficient of linear expansion for copper is $$1.7 	imes 10$$^{-5}$$\ \mathrm{K}^{-1}$$, what is the increase in length of the rod?

Accepted Answer

$$1.7 	imes 10$$^{-3}$$\ \mathrm{m}$$

Question 9

Which of the following is NOT a correct application of the first law of thermodynamics?

Accepted Answer

The internal energy of a system increases if heat is removed and the system does work.

Question 10

A $$0.5\ \mathrm{kg}$$ mass attached to a string is swung in a horizontal circle of radius $$2\ \mathrm{m} at a $$speed of $$4\ \mathrm{m/s}. $$What is the tension in the string?

Accepted Answer

$$16\ \mathrm{N}$$

Question 11

Which of the following best describes the Doppler effect?

Accepted Answer

The apparent change in frequency of a wave due to the relative motion between the source and the observer.

Question 12

A gas undergoes an isothermal expansion at $$300\ \mathrm{K}$$, doubling its volume. What happens to the pressure of the gas?

Accepted Answer

It is halved.

Question 13

Which of the following is a correct statement about resonance in mechanical systems?

Accepted Answer

Resonance occurs when the frequency of an external force matches the natural frequency of the system, resulting in large amplitude oscillations.

Question 14

A $$5\ \mathrm{kg}$$ block slides down a frictionless incline of height $$10\ \mathrm{m}. $$What is the kinetic energy of the block at the bottom of the incline?

Accepted Answer

$$490\ \mathrm{J}$$

Question 15

Which of the following is the correct expression for the root mean square (rms) speed of molecules in an ideal gas?

Accepted Answer

$$v_{\mathrm{rms}} = \sqrt{\frac{3k_B T}{m}}$$

Question 16

A $$0.2\ \mathrm{kg}$$ mass oscillates on a spring with amplitude $$0.1\ \mathrm{m}$$ and period $$0.5\ \mathrm{s}. $$What is the maximum speed of the mass?

Accepted Answer

$$1.26\ \mathrm{m/s}$$

Question 17

Which of the following is a correct statement about the propagation of sound waves in air?

Accepted Answer

Sound waves in air are longitudinal waves that require a medium to propagate.

Question 18

A $$1\ \mathrm{kg}$$ block at $$20^{\circ}$$\mathrm{C}$$ absorbs 4200$$\ \mathrm{J}$$ of heat. If the specific heat capacity of the material is 4200$$\ \mathrm{J/kg\cdot K}$$, what is the final temperature of the block?

Accepted Answer

$$21^{\circ}$$\mathrm{C}$$

Question 19

Which of the following best describes the physical meaning of entropy?

Accepted Answer

Entropy is a measure of the disorder or randomness of a system.

General Physics II (PHYS102) - Syllabus and Study Guide

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