If a parabolic reflector is 20 cm in diameter and 5 cm deep, find the focus.

If a parabolic reflector is 20 cm in diameter and 5 cm deep, find its focus.

A parabola reflector is 9 cm deep and its diameter is 24 cm. Find the distance of its focus from vertex.

A parabola reflector is 15 cm deep and its focus is at a distance of 5 cm from its vertex. Find the diameter of the reflector.

The focus of a parabolic mirror is at a distance of 6 cm from its vertex. If the mirror is 20 cm deep, find the distance LM.

A bucket is 32 cm in diameter at the top and 20 cm in diameter at the bottom. Find the capacity of bucket in litres if it is 21 cm deep. Also find the cost of tin sheet used in making the bucket at the rate of Rs 1.50 per sq dm.

The height of a circular cyclinder is 20 cm and the diamete rof its bases is 4cm . Find : its volume (ii) its total surface area

The diameter of a circle is 9 cm, find its radius.

Find the number of coins, 1.5 cm in diameter and 0.2 cm thick, to be melted to form a right circular cylinder of height 10 cm and diameter 4.5 cm.

Find the number of coins, 1.5 cm in diameter and 0.2 cm thick, to be melted to form a right circular cylinder of height 10 cm and diameter 4.5 cm.

A conical paper cup 20 cm across the top and 15 cm deep is full of water. The cup springs a leak at the bottom and losses water at 5 cu. cm per minute. How fast is the water level dropping at the instant when the water is exactly 7.5 cm deep ?