H K Dass, Rama Verma and, Bhagwat Swarup Sharma Solutions for Chapter: Surface Areas & Volumes, Exercise 2: EXERCISE

A toy is in the shape of a cylinder with two equal cones stuck to each other of its ends. The length of entire solid is $30 \mathrm{cm}$ and diameter of cylinder and cones $10.5 \mathrm{cm}$ and the length of the cylinder is $14 \mathrm{cm}$. If its surface area is$k {\mathrm{cm}}^2$ (correct up to two decimal places) then find $k$.​ (Take $\mathrm{\pi }=\frac{22}{7}$)

A medicine capsule is in the shape of a cylinder with two hemispheres stuck to each of its ends. The length of the entire capsule is $16 \mathrm{mm}$ and the diameter of the capsule is $14 \mathrm{mm}$. If its surface area is $k {\mathrm{mm}}^2$ then find $k$.

Rasika purchased a candle from market for Diwali festival. The shape of the candle is shown in Fig. She purchased a packet of $24$ candles. If the surface areas of candles is$k {\mathrm{cm}}^2$ then find the value of $k$ correct up to one decimal places. (Take $\mathrm{\pi }=\frac{22}{7}$)

A wooden belan was made from a big cylinder and two equal small cylinders to flatten the dough as shown in the figure. If the surface area of the belan is $k {\mathrm{cm}}^2$ then find $k$​. (Take $\mathrm{\pi }=\frac{22}{7}$)

A pulley was made from two big equal cylinders stuck at the end of a small cylinder to draw water from the well, as shown in the figure. If its curved surface area is $k {\mathrm{cm}}^2$ then find $k$.

A wooden toy was made by scooping out a hemisphere from each end of a cylinder. If the height of the cylinder is $20 \mathrm{cm}$ and its base is of diameter $14 \mathrm{cm}$, if the total surface area of the toy when it is ready is $k {\mathrm{cm}}^2$ then find $k$.

A decorative block is made of two solids: a cube and a hemisphere. The base of the block is a cube with edge of $7 \mathrm{cm}$ and the hemisphere attached on the top has a diameter of $4.9 \mathrm{cm}$. If the block is to be painted, if the area to be painted is $k {\mathrm{cm}}^2$ then find $k$.

A decorative block is made up of cube and cone. The base of the block is the cube with edge of $6 \mathrm{cm}$ and the cone attached on the top has a diameter of $5.6 \mathrm{cm}$ and height of $1.4 \mathrm{cm}$. If the block is to be painted red at the rate of $₹ 0.45 \mathrm{per} \mathrm{cm}²$, Find the surface area to be painted and the cost of painting the block.