How do the oral histories in source 5 add to your understanding of home front involvement in the war effort? Does their testimony force you to question the other documents in any way, and if so, how?

Two positive lenses with focal lengths of 0.30 m and 0.50 m are separated by a distance of 0.20 m. A small butterfly rests on the central axis 0.50 m in front of the first lens. Locate the resulting image with respect to the second lens.

Janeesa's backpack has 4 pens and 6 pencils in the front pocket. She reaches in, grabs one, and removes it. Then she reaches in again, grabs another, and removes it. Are these two events independent or dependent? Justify.

We would like to place an object 45 cm in front of a lens and have its image appear on a screen 90 cm behind the lens. What must be the focal length of the appropriate positive lens?

A small aircraft has a wing area of $35 \mathrm{m}^{2},$ a lift coefficient of 0.45 at takeoff settings, and a total mass of 4000 kg. Determine (a) the takeoff speed of this aircraft at sea level at standard atmospheric conditions, (b) the wing loading, and (c) the required power to maintain a constant cruising speed of 300 km/h for a cruising drag coefficient of 0.035.

Steve, Derrin, Sid, Spencer, and Naji are waiting in line to buy tickets to a movie. Derrin is in front of Spencer and behind Sid. Steve is between Sid and Derrin. Naji is behind Spencer. Who is first in line?

A moth at about eye level is 10 cm in front of a plane mirror; you are behind the moth, 30 cm from the mirror.What is the distance between your eyes and the apparent position of the moth’s image in the mirror?

What is the focal length of a thin plano-convex lens. The front surface of this lens is flat, and the rear surface has a radius of curvature of $R_2=-35 \mathrm{~cm}$? Assume that the index of refraction of the lens is $1.5$.

A piston/cylinder assembly contains water at $200$ $\mathrm{kPa}, 200^{\circ} \mathrm{C}$ with a volume of $20 \mathrm{~L}$. The piston is moved slowly, compressing the water to a pressure of $800\ \mathrm{kPa}$. The loading on the piston is such that the product $P V$ is a constant. Assuming that the room temperature is $20^{\circ} \mathrm{C}$, show that this process does not violate the second law.

In $3 \mathrm{~sec}$, Penny walks $24 \mathrm{~ft}$ to the bow (front) of a tugboat. The boat is cruising at a rate of $5 \mathrm{~ft} / \mathrm{sec}$. What is Penny's rate of travel with respect to land?

Suppose you stand in front of a tall rock wall that is 170 meters away. If you yell, how long does it take for the echo to get back to your ears if the speed of sound is 340 m/s?

A spider hangs by a strand of silk at an eye level 30 cm in front of a plane mirror. You are 65 cm behind the spider. Show that the distance between your eye and the image of the spider in the mirror is 1.25 m.

Using the average atomic masses given inside the front cover of this book, calculate the mass in grams of each of the following samples.

c. $0.00101 \mathrm{~mol}$ of iron(II) sulfate, $\text{FeSO}_4$

At a rock concert, a $\mathrm{dB}$ meter registered $130 \mathrm{~dB}$ when placed $2.5 \mathrm{~m}$ in front of a loudspeaker on stage. How far away would the sound level be $85 \mathrm{~dB}$ ?