CBSE Class 10-Mathematics: Chapter –13 Surface Areas and Volumes Part 3
Doorsteptutor material for CBSE is prepared by world's top subject experts: fully solved questions with step-by-step explanation- practice your way to success.
Question 10:
Two right circular cones are made having times the radius of Y and Yhaving half the volume of . Calculate the ratio of heights of .
Answer:
Let radius of cone
Radius of Cone
Question 11:
If the areas of three adjacent faces of cuboid are respectively, find the volume of the cuboids.
Answer:
Volume of cuboid
Questions 12:
A shuttlecock used for playing badminton has the shape of a frustum of a cone mounted on a hemisphere. The external diameters of the frustum are , and the height of the entire shuttlecock is . Find the external surface area.
Answer:
of lower end of frustum
of upper end
of frustum
External surface area of shuttlecock
On substituting we get,
Question 13:
A conical vessel of radius and height is filled with water. A sphere is lowered into the water and its size is such that when it touches the sides, it is just immersed as shown in the figure. What fraction of water flows out?
Answer:
This problem can be done in many ways
Let “r” be the radius of sphere
In right triangle
Volume of that flows out of cone volume of sphere
Fraction of water overflows
Question 14:
A golf ball has a diameter equal to . Its surface has dimples each of radius . Calculate the total surface area which is exposed to the surroundings assuming that the dimples are hemispherical
Answer:
of ball
TSA exposed to surroundings