The altitude of a cone is 20 cm and its semi-vertical angle is `30^@.` If the semi-vertical angle is increasing at the rate of `2^@` per second, then the radius of the base is increasing at the rate of

The altitude of a cone is 20 cm and its semi-vertical angle is 30^0 . If the semi-vertical angle is increasing at the rate of 2^0 per second, then the radius of the base is increasing at the rate of (a) 30 cm/sec (b) 160/3 cm/sec (c) 10 cm/sec (d) 160 cm/sec

If the radius of a circle is increasing at the rate of 2 cm/ sec, then the area of the circle when its radius is 20 cm is increasing at the rate of

The radius of spherical balloon is increasing at the rate of 5 cm per second. At what rate is the surface of the balloon increasing, when the radius is 10 cm?

The height of a right circular cone is 40 cm and semi-vertical angle is 30^@ , the slant height of the cone is =?

The radius of spherical balloon is increasing at the rate 5 cm per second. At what rate is the surface of the balloon increasing, when the radius is 10 cm?

A cone of semi vertical angle of alpha is inscribed in a sphere of radius 2 cm. the height of the cone is

If the edge of a cube increases at the rate of 60cm per second, at what rate the volume in increasing when the edge is 90cm

A water is poured into an inverted cone whose semi-vertical angle is 45^(@) so that the level of water increases at the rate of 1 cm/sec. then the rate at which the volume of water is increasing when height of water in cone is 2 cm is

If water is poured into an inverted hollow cone whose semi-vertical angle is 30^0 , so that its depth (measured along the axis) increases at the rate of 1 cm/sec. Find the rate at which the volume of water is increasing when the depth is 2 cm.

Perimeter of an isoscels triangle is 100 cm . If its base increase at the rate of 2cm // min , the, when base is 30cm , its altitude is changing at the rate of