      Q) Both the ends of a metallic solid cylinder are semi-spherical. Its total height is 19 cm and diameter of the cylinder is 7 cm. Find the weight of the solid if weight of 1 cm³ of the metal is 4.5 g. Ans: Step 1: Let’s make diagram for our […]
surface areas and volumes
Q) Find the number of bricks, each measuring 25 cm x 12.5 cm x 7.5 cm, required to construct a wall 24 m long, 20 m high and 0.5 m thick while the cement and sand mixture occupies 1/20th of the volume of the wall. Ans:Â [Approach: A wall consists of bricks and sand-cement mixture.
      Q) A cone and a cylinder have the same base radius and height. If the volume of the cylinder is 300 cm 3, find the volume of the cone. Ans: [Approach: Given that the radius and height are the same, we will find a relation of r and h from
Q) Rinku was very happy to receive a fancy jumbo pencil from his best friend Rohan on his birthday. Pencil is a basic writing tool, when sharpened its shape is a combination of cylinder & cone as given in the picture. Cylindrical pencil with conical head is a common shape worldwide since ages. Commonly pencils are
Q) In the adjoining diagram, a tilted right circular cylindrical vessel with base diameter 7 cm contains a liquid. When placed vertically, the height of the liquid in the vessel is the mean of two heights shown in the diagram. Find the area of wet surface, when the cylinder is placed vertically on a horizontal
Q) A manufacturing company prepares spherical ball bearings, each of radius 7 mm and mass 4 gm. These ball bearings are packed into boxes. Each box can have maximum of 2156 cm 3Â of ball bearings. Find the: (a) maximum number of ball bearings that each box can have. (b) mass of each box of ball
Q) A cylindrical tub, whose diameter is 12 cm and height 15 cm is full of ice-cream. The whole ice-cream is to be divided into 10 children in equal ice-cream cones, with conical base surmounted by hemispherical top. If the height of conical portion is twice the diameter of base, find the diameter of conical
Q) A metallic solid sphere of radius 10.5 cm melted and recasted into smaller solid cones each of radius 3.5 cm and height 3 cm. How may cones will be made? Ans: Step 1: Let’s draw a diagram to better understand the question: Here, according to question, we have sphere of radius 10.5 cm. This
Q) A wooden article was made by scooping out a hemisphere from each end of a solid cylinder, as shown in the figure. If the height of the cylinder is 5·8 cm and its base is of radius 2·1 cm, find the total surface area of the article. Ans: Let’s make a diagram marking all
A wooden article was made by scooping out a hemisphere from each Read More »
Q) Tamper-proof tetra-packed milk guarantees both freshness and security. This milk ensures uncompromised quality, preserving the nutritional values within and making it a reliable choice for health-conscious individuals. 500 mL milk is packed in a cuboidal container of dimensions 15 cm x 8 cm x 5 cm. These milk packets are then packed in cuboidal