Consider two converging lenses. The lens on the left has a focal length of 20mm. The second lens, which is placed 65mm to the right of the first lens, has a focal length of 40mm. A small object (height 1.2mm) is placed 90mm to the left of the first lens.

1. Sketch a basic diagram of the situation, including the object, both lenses, and their focal points.

2. Calculate the position and height of the image created by the leftmost lens. Add that image to your diagram. Pay special attention to the location of that image relative to the other items on your diagram.

3. Now calculate the height of the image produced by the rightmost lens. If a person looking into the rightmost lens from the right side, would they be able to see small details in the object? Based on your diagram, what causes this particular effect?

4. Imagine that we move the rightmost lens 1mm to the right. What would a person looking into it from that side see now? Why is this result different from before? The effect you saw in part 3, that the image is both visible and heavily magnified if the object is ever so slightly within the focal length, is a key component of two important optical devices. The one we just looked at is a microscope, magnifying an object that is close by.

5. For a telescope, the object is very, very far away. Using the same lenses as before, where should we place the rightmost lens to get a heavily magnified image of Jupiter?

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?

Fill in the blanks with the numbers is a measure of the resistance to flow. a high liquid has a high resistance to flow and flows slowly. the ancients thought everything in the world was made of 4 we now know that there are 94 naturally occurring and scientists have created another 24 i am certain they will create even more. honey flows slowly because it has a high to flowing. a can be separated by physical means because it contains more than one pure substance and 2 pure substances are not chemically bonded to each other. a cannot be separated by physical means. all matter is made up of all elements are with the same number of protons. if it is just a single or many bonded together, if all of them have the same number of protons, it is an element. in a piece of pure iron metal, all the are joined together, that piece of iron metal is called elemental iron. a single of iron is called elemental iron. a mixture has differences from place to place. we might need a microscope to see them or they might be obvious to the unaided eye. there are surfaces separating it into different phases. a mixture is the same everywhere. it is uniform. there are no surfaces separating it into different phases. if different kinds of atoms (different elements) are bonded together by their electrons, it is called a there are physical means of to isolate the different pure substances in a mixture and there are chemical means of to isolate the different elements in a compound. 1. element 2. compound 3. mixture 4. heterogeneous 5. homogeneous 6. pure substance 7. atoms 8. separation 9. viscosity 10. resistance