.
The Stefan-Boltzmann Law gives the energy radiation <em>per unit area</em> of a black body:
where,
.
.
.
Keep as many significant figures in as possible. The error will be large when
is raised to the power of four. Also, the real value will be much smaller than
since the emittance of a human body is much smaller than assumed.
Answer:
8977.7 kg/m^3
Explanation:
Volume of water displaced = 55 cm^3 = 55 x 10^-6 m^3
Reading of balance when block is immersed in water = 4.3 N
According to the Archimedes principle, when a body is immersed n a liquid partly or wholly, then there is a loss in the weight of body which is called upthrust or buoyant force. this buoyant force is equal to the weight of liquid displaced by the body.
Buoyant force = weight of the water displaced by the block
Buoyant force = Volume of water displaced x density of water x g
= 55 x 10^-6 x 1000 x .8 = 0.539 N
True weight of the body = Weight of body in water + buoyant force
m g = 4.3 + 0.539 = 4.839
m = 0.4937 kg
Density of block = mass of block / volume of block
=
Density of block = 8977.7 kg/m^3