D
Numericals:
1. A rectangular field is of length 80 m and breadth 45 m. Find the area of the field., (Ans. 3600 m)
2. Calculate the volume of wood of mass 200 kg, given the density of wood is 800 kg/m3. (Ans. 0.25 m)
3. Density of kerosene is 0.3 g/cm². Convert it in the SI system of unit.
(Ans. 800 kg/m)
4. The volume of a metal cube is 125 cm. When the density of the metal is 13.6 g/cm, find the mass of
the metal cube in kilograms.
(Ans. 1.7 kg)
Answers
Answer:
Ans - 1.
Explanation:
Area of rectangle = l×b (length × breadth)
Area = 80m ×45m
Area = 3600m
Area of rectangular field is 3600 m.
Answer:
1. 3600m²
2. 0.25m³(S.I. unit of volume is m³=side×side×side=m×m×m=m³)
3. 3000kg/m(The ans should be this)
4. 1.7kg
Explanation:
1. Given that:-
Length of the rectangular field=80m.
Breadth of the rectangular field=45m.
therefore,
The area of the rectangular field=length×breath
=(80×45)m²
=3600m²(ans).
2. Given that:-
Density of wood is 800 kg/m³.
Mass of wood is 200 kg.
We know that:-
Density=Mass/Volume
therefore,
Volume=Mass/Density
=)Volume=200/800
=)Volume=1/4=0.25m³(ans)
3. Given that:-
Density = 0.3g/cm³
We that:-
1kg/m³=1kg/1m³
=1000g/(100cm)³
= 1g/1000cm
Thus we can conclude that:-
To convert density into S.I. unit=density×1000kg/m³.
To convert density into S.I. unit=density÷1000kg/m³.
Hence, Density of kerosene is 0.3 g/cm² in S.I. unit:
0.3×1000=3000kg/m³ (ans)
4. Given that:-
Volume of a metal cube is 125 cm.
Density of a metal cube is 13.6 g/cm.
We know that:-
Density=Mass/Volume
therefore,
Mass=Volume×Density
=) Mass=125×13.6
=) Mass=1700cm
To convert mass of the metal cube in the S.I. unit:
(1700/1000)m=1.7m (ans).