Answer:
(e) thermal expansion
Explanation:
The density, the heat of fusion and the melting temperature of the metal are determining characteristics to take into account to raise the temperature of the metal from room temperature to the melting temperature. Since they will determine the following:
Density: is the relationship between the mass of a body and the volume it occupies in outer space.
Heat of fusion: The enthalpy of fusion or heat of fusion is the amount of energy needed to make a mole of an element that is at its melting point pass from the solid state to the liquid, at constant pressure.
Melting temperature is defined as the temperature at which the phase transition from the solid state to the liquid occurs at normal atmospheric pressure.
While the dilution of metals will only have an influence on the volume it will occupy but not on the heating process
The density of the fluid is 776.3 
<u>Explanation:</u>
Buoyant force is the upward pushing force whenever an object is trying to get immersed in fluid. So this is the force given by the fluid on the object which is trying to get immersed. The buoyant force is found to be directly proportional to the product of density of the object, volume of the object. And here the acceleration due to gravity will be acting as proportionality constant.
As, buoyant force is given as 671 N and volume is 0.0882 
and acceleration is known as 9.8 m/
. Then density is
Thus,
Density is 776.3 kg .
Answer:
Explanation:
Near point = 56 cm .
near point of healthy person = 25 cm
person suffers from long sightedness
convex lens will be required .
object distance u = 25 cm
image distance v = 56 cm
both will be negative as both are in front of the lens.
lens formula
I/v - 1 / u = 1/f
- 1/56 +1/25 = 1/f
- .01785 + .04 = 1/f
1/f = .02215
f = 45.15 cm .
