Two airplanes flying 1.0 km apart at the same altitude spot a target ahead of them on the ground. the angles of depression subtended by the target at the two airplanes are 45o and 37o. the airplanes and the target are in the same vertical plane. what is the altitude (in meters) at which the planes are flying? (note: for the distances involved, the earth can be considered as flat.)
a. 2900
b. 3060
c. 1000
d. 2000

Like a key in a lock, the shape of the. must bind with the. of the recieving neuron

Follow these directions and answer the questions. 1. set up the ripple tank as in previous investigations. 2. bend the rubber tube to form a "concave mirror" and place in the ripple tank. the water level must be below the top of the hose. 3. generate a few straight pulses with the dowel and observe the reflected waves. do the waves focus (come together) upon reflection? can you locate the place where the waves meet? 4. touch the water surface where the waves converged. what happens to the reflected wave? 5. move your finger twice that distance from the hose (2f = c of c, center of the curvature) and touch the water again. does the image (the reflected wave) appear in the same location (c of c)? you may have to experiment before you find the exact location. sometimes it is hard to visualize with the ripple tank because the waves move so quickly. likewise, it is impossible to "see" light waves because they have such small wavelengths and move at the speed of light. however, both are examples of transverse waves and behave in the same way when a parallel wave fronts hit a curved surface.

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle