Answer: 9300 kcal
Explanation: Given: Latent heat of fusion of aluminum is 93 kcal/kg.
That is for melting 1 kg of aluminium at 660 amount of heat required is = 93kcal
Thus for 100 kg of aluminium at 660 amount of heat required is=
Thus the amount of energy needed to melt 100 kg of aluminum at the melting point is 9300 kcal.
<h2>Book will hit the foot with force 21.8 N</h2>
Explanation:
The momentum of any object = m v
here m is the mass of body and v is its velocity
Thus momentum P = 3.2 x 1 = 3.2 kg-m
As the book is falling freely , so it will fall with and acceleration g
The force exerted by it is = m g
Thus force = 2.18 x 10 = 21.8 N
<span>Electrons display some properties of waves and while they reside outside of the nucleus, their positions cannot be known with certainty. </span>
Answer:
Explanation:
According to the Stefan-Boltzmann law for real radiating bodies:
(1)
Where:
is the energy radiated (in Watts)
is the Stefan-Boltzmann's constant.
is the Surface area of the body
is the effective temperature of the body (its surface absolute temperature) in Kelvin
is the body's emissivity
On the other hand, we are told the human body is roughly approximated to a cylinder of length and circumference .
The circumference of a circle is: where is the radius. Hence .
Now we have to input this value for in the Area of a cylinder formula:
(2)
Substituting (2) in (1):
(3)
Finally: