2. Car A and B leave a town at the same time. Car A heads due north at a rate of 75km/hr and car B heads due east at a rate of 80 km/hr. How fast is the distance between the cars increasing after four hours? Town

3. A 20 ft long ladder is leaning against a wall and sliding toward the floor. If the foot of the ladder is sliding away from the base of the wall at a rate of 10 ft/sec, a) how fast is the top of the ladder sliding down the wall when the top of the ladder is 12 ft. from the ground?

4. A 20 ft long ladder is leaning against a wall and sliding toward the floor. If the foot of the ladder is sliding away from the base of the wall at a rate of 10 ft/sec, b) find the rate at which the angle between the ladder and the wall is changing when the top of the ladder is 12 ft. from the ground?

5. A girl 4 feet tall walks at a rate of 1.5 ft/sec away from a light that is 10 feet above the ground. At what rate is the length of her shadow changing when she is 8 feet from the base of the light?

6. Suppose senior board decided to throw a graduation bash and the coca cola is flowing freely from the bottom of a giant cone-shaped barrel which is 12 feet deep and 6 feet in radius at the top. If the coke is disappearing at a rate of 6 cubic feet per hour, at what rate is the depth of the coke in the tank going down when the depth is 4 feet?

7. A student is using a straw to drink from a conical paper cup at a rate of 3 cubic centimeters a second. If the height of the cup is 10 cm. and the diameter of its opening is 6 cm., how fast is the level of the liquid falling when the depth of the liquid is 5 cm?

8. A piece of ice in the shape of a cube melts uniformly so that its volume decreases at 3 cm 3 /sec. How fast is its surface area decreasing when the edge of the cube is 5 cm.?