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.

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?

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.

An object of height $3.0 \mathrm{~cm}$ is placed $5.0 \mathrm{~cm}$ in front of a converging lens of focal length $20 \mathrm{~cm}$ and observed from the other side. Where and how large is the image?

The solid 30-mm-diameter steel $[E=200 \mathrm{GPa}]$ shaft shown in Figure P10.32 supports two belt pulleys. Assume that the bearing at $A$ can be idealized as a pin support and that the bearing at $E$ can be idealized as a roller support. For the loading shown, use discontinuity functions to compute (a) the shaft deflection at pulley $B$. (b) the shaft deflection at point $C$.

The cube contains positive charge. The electric field is constant over each face of the cube. Does the missing electric field vector on the front face point in or out? What is the minimum possible field strength?

From the front to the back of the property Wally stepped off 40 paces. He estimated that each pace was a yard. Convert 40 yards to feet using a unit multiplier to estimate the depth of the property in feet.

A transparent photographic slide is placed in front of a converging lens with a focal length of 2.44 cm. An image of the slide is formed 12.9 cm from the slide. How far is the lens from the slide if the image is real?

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 $1.5$.

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 $85 \mathrm{~dB}$ ?

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.

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.

A car has a circular turning radius of 16.1 ft. the distance between the two front tires is 4.7 ft. How much farther does a tire on the outside of the turn travel than a tire on the inside?

A ball whose diameter is $0.25 \mathrm{~cm}$ is placed $50 \mathrm{~cm}$ in front of a convex spherical mirror. If the focal length of the mirror is $-40 \mathrm{~cm}$, what is the diameter of the ball as viewed in the mirror?