Question

a piece of metal pipe is 35cm long.the inner diameter of cross section is 14cm and outer diameter is 16cm.if the weight of metal is 10gms per cm cube,what is the weight of piece of pipe

Answer 1

Vol of metal used=22[8^2-7^2]35/7
=22[64-49]5=110*15=1650cu cm
Weight of metal pr cm cube is 10gm
Weight of metal 1650 cm cube=1650*10=16500gm =16.500kg

Answer 2

Answer:

16485g

Step-by-step explanation:

Height of pipe = 35 cm

Inner diameter = 14 cm

Inner Radius = $\frac{Diameter}{2} =\frac{14}{2}=7 cm$

Outer diameter = 16cm.

Outer Radius = $\frac{Diameter}{2} =\frac{16}{2}=8 cm$

Since pipe is in the form of cylinder

Volume of cylinder = $\pi r^{2} h$

So, volume of pipe with inner radius = $3.14 \times 7^{2} \times 35$

                                                            = $5385.1 cm^3$

Volume of pipe with outer radius =  = $3.14 \times 8^{2} \times 35$

                                                            = $7033.6 cm^3$

So, the volume of metal used = Volume of pipe with outer radius -  volume of pipe with inner radius

                                                  = $7033.6- 5385.1$

                                                   = $1648.5cm^3$

Now, the weight of metal is 10gms per cm cube

So, weight of 1648.5 cubic cm metal = $1648.5\times10$

                                                          = $16485g$

Hence the weight of the piece of pipe is 16485g