A piece of iron has a volume of 75 cm3
and mass is 585 g. Find the density of iron in
(a) g cm-3
(b) kg m-3
Answers
A piece of iron has a volume of 75 cm3
and mass is 585 g. Find the density of iron in
(a) g cm-3
(b) kg m-3
What's your doubt?
Physics
Bookmark
If a block of iron of density 5g/cm
3
and size 5cm×5cm×5cm was weighed whilst completely submerged in water, what would be the apparent weight in g−f(gram−force)?
share
Share
Answer
Density of block =5 gm/cm
2
Volume of block V=(5×5×5)cm
3
=125cm
3
Mass of block.M=density × volume
=5×125
=325 gm=0625 kg
Density of water, ρ=1 gm/cm
3
On submerging the iron block completely into water the apparent weight of the block is given from the box of the container
Drawing free body diagram of the block
Now as the block is stationery upwards and downward form on the block should balance each other
Thus. N+F
B
=Mg
Now, F
B
= density of water × volume of block × g
=(1 gm/cm
3
)×(125cm
3
)×(98 m/s
2
)
=(125 gm)×(98 m/s
2
)
=(0.125×9.8) kgm/s
2
=(0.125×9.8)N(1 N=1 kgm/s
2
)
Putting values is (1)
N=(0.625×9.8)−(0.125×9.8) Newton
⇒ Apparent weight =(0.5×9.8) Newton
(∵ Apparent weight = normal force)
Now, 1 gf(gram−force)=9.8×10
−3
N
⇒1 N=
9.8
1
×10
3
gf
Thus, Apparent weight +(0.5×9.8)×(
9.8
1
×10
3
)
=500 gf
Hence apparent weight of the block completely submerged in water is 500 gram- force
hope it helps you