Calculate the volume of a sheet of aluminium weighing 1350 g, density of aluminium is 2.7 g cm-³
Answers
Answer:
Ncert solutions
Grade 8
Mathematics
Science
Chapters in NCERT Solutions - Mathematics , Class 8
Exercises in Mensuration
Question 3
Q3) The shape of a garden is rectangular in the middle and semi circular at the ends as shown in the diagram. Find the area and the perimeter of this garden [Length of rectangle is 20 – (3.5 + 3.5) metres].
Solution 3:
We know that,
length of the garden=20 m
diameter of semicircle=7m,r=3.5m
(breadth of the rectangle)
Length of rectangle=20m-3.5m-3.5m20m−3.5m−3.5m
=13 m
Area of rectangle=length\times breadthlength×breadth
=13m\times7m=13m×7m
=91\ m^2=91 m
2
Area of semi-circle =\frac{1\ }{2}\times\pi\times\left(3.5\right)^2
2
1
×π×(3.5)
2
==\frac{1}{2}\times\frac{22}{7}\times\frac{35}{10\ }\times\frac{35}{10}=
2
1
×
7
22
×
10
35
×
10
35
=19.25\ m^2=19.25 m
2
Area of garden=91+19.25+19.2591+19.25+19.25
=129.5\ m^2=129.5 m
2
Perimeter of garden=perimeter of rectangle+2(Perimeter of semicircle)
Perimeter of rectangle==2\times length=2×length
=2\times26=2×26
=26\ m=26 m
Perimeter of semicircle==\pi r=πr
=\frac{22}{7}\times3.5=
7
22
×3.5
=\frac{22}{7}\times\frac{35}{10}=
7
22
×
10
35
=11m
Perimeter of Garden=26m+11m+11
=48m
Answer
Given: Weight =675g
Density =2.7g/cm
3
Density=
Volume
Mass
⇒2.7gm/cm
3
=
V(cm
3
)
675g
⇒V=
2.7
675
cm
3
⇒V=250cm
3