The radius of a hemispherical balloon increases from 6 cm to 12 cm as air is being pumped in to it. The ratios ofthe surface areas of the balloon in the two cases is

A spherical balloon with radius r inches has volume V(r) = 43𝜋r3. Find an expression that represents the amount of air required to inflate the balloon from a radius of r inches to a radius of r + 2 inches. (Express your answer in terms of 𝜋 and r.)

A spherical balloon is filled with air at the constant rate of 200cm2s.Calculate the rate at which the radius is increasing when the radius is10cm.1

A meteorological balloon rises through the atmosphere until it expands to a volume of 1.0 × 10 6 m 3, wherethe pressure is 1.0 × 10 3 Pa. The temperature also falls from 17 °C to − 43 °C.The pressure of the atmosphere at the Earth’s surface = 1.0 × 10 5 Pa.Show that the volume of the balloon at take off is about 1.3 × 10 4 m 3

Air pressure: Air pressure is the force exerted by the weight of the air in the Earth's atmosphere on objects on or near its surface.If we blowing the balloon so which area of balloon experience more air pressure?

A spherical balloon is released from rest and expands as it rises. After rising for t seconds, its radius is r cm, and its surface area is A cm2, where A = 4r2. The initial radius of the balloon is 16 cm. Given that the rate of increase of the radius is constant and has the value of 0.8 cm s– 1, find the rate of increase of A when t = 5.