1. An airplane is flying towards a radar station at a constant height of 6 km above the ground. If the distance s between the airplane and the radar station is decreasing at a rate of 400 km per hour when s 10 km., what is the horizontal speed of the plane? = 2. A light is on the ground 20 m from a building. A man 2 m tall walks from the light directly toward the building at 1 m/s. How fast is the length of his shadow on the building changing when he is 14 m from the building? 3.) A conical cup is 4 cm across and 6 cm deep. Water leaks out of the bottom at the rate of 2 cm'/sec. How fast is the water level dropping when the height of the water is 3 cm? A person 2 m tall walks towards a lamppost on level ground at a rate of 0.5 m/sec. The lamp on the post is 5 m high. How fast is the length of the person's shadow decreasing when the person is 3 m from the post? 3 5. Air is escaping from a spherical balloon at the rate of 2 cm per minute. How fast is the surface 4r where V is the volume area shrinking when the radius is 1 cm? V= 4/3 r and S = and S is the surface area, r is the radius.