Two blocks are stacked on top of each other on thefloor of an elevator. For each of the following situations, selectthe correct relationship between the magnitudes of the two forcesgiven.

You will be asked two questions about each of threesituations. Each situation is described above the first in the pairof questions. Do not assume anything about a given situation exceptfor what is given in the description for that particularsituation.

In each ofthe following questions, the answer is one of thefollowing:
greaterthan, equal to, less than, or unknown compared to.
Firstsituation
The elevator is moving downward ata constant speed.
1. The force of the bottomblock on the top block is theforce of the earth on the top block.
2. The force of the bottom block on topblock is the force of the topblock on bottom block.
Secondsituation
The elevator is moving downward atan increasing speed.
1. The force ofthe bottom block on the top block is the force of the earth on the top block.
2. The force ofthe bottom block on the top block is the force of the top block on the bottom block.
Thirdsituation
The elevator is moving upward.
1. The force of the bottom block on thetop block is the force of theearth on the top block.
2. The force of the bottom block on thetop block is the force of thetop block on the bottom block.

Follow these directions and answer the questions. 1. shine a pencil-thin beam of light on a mirror perpendicular to its surface. (if you don't have a laser light as suggested in the video, you can make a narrow beam from a flashlight by making a cone from black construction paper and taping it over the face of the flashlight.) how does the light reflect? how does the relationship of incident to reflected ray relate to the reflection of water waves moving perpendicular to a barrier? 2. shine a pencil-thin beam of light on a mirror standing on a sheet of paper on the table (or floor) so that you can mark the incident ray and reflected ray. (you can support the mirror from the back by taping it to a wooden block.) 3. mark a line on the paper representing the reflective surface. (the reflective surface of a mirror is usually the back edge.) 4. draw a dashed line perpendicular to the mirror surface at a point where the incident and reflected ray meet. this perpendicular is called a normal to the surface. 5. measure the angles between the rays and the normal. the angle of incidence is the angle formed by the incident ray and the normal to the surface. the angle formed by the reflected ray and normal is called the angle of reflection (r). what is the angle of incidence? what is the angle of reflection? 6. repeat for several different angles. (see report sheet for details.) what appears to be the relationship between the angle of incidence and angle of reflection? in science 1204, what was the relationship for these two angles made by the reflection of waves in a ripple tank? 7. roll a ball bearing so that it hits a fixed, hard surface (a metal plate) at several angles (including head-on). observe the way in which the ball bearing reflects. what generalization can you make about how a ball bearing reflects from a wall? have you proved that light can only behave like a wave?

Photoelectrons with a maximum speed of 6.50 x 107 m/s are ejected from a surface in the presence of light with a frequency of 6.75 x 1014hz. if the mass of an electron is 9.10 x 10-31 kg, calculate in joules the maximum kinetic energy of a single electron. 3.84 x 10-15 j 1.92 x 10-15 j 5.92 x 10-23 j 3.07 x 10-16 j

If the ama of the inclined plane below is 2, calculate the ima and efficiency. ima = efficiency =