1.) A boy is walking toward the base of a pole 20 m high at the rate of 4 km/h. At what rate (in meters per second) is the distance from his feet to the top of the pole changing when he is 5 m from the pole? Present your answer rounded or truncated to three decimal places. 2.) If the radius of a sphere is increasing at 1 cm/s, find the rate of change of its volume when the radius is 6 cm. Present your answer in terms of r. 3.) If the radius of a sphere is increasing at the constant rate of 2 cm/min, find the rate of change of its surface area when the radius is 100 cm. Present your answer in terms of r. If possible could you please do these 3 question. :(( I am very confused on them! Thank you