Since there is no diagram I can see to prove my answer, I must infer that a heat source should be applied to the solid substance and cause the atoms in the solid to spread further apart and become a different state, in which atoms will be able to freely move, gas.
It increases confidence because the more times you conduct the same experiment over and over should either prove your hypothesis right and wrong and eliminate any random occurrences that might affect your results.
Answer:
(1) it is transparent so it makes the reading difficult. (2) it is volatile. (3) it is a poor conductor of heat. (4) it has a higher specific heat capacity, so it absorbs more heat from the body with which it is kept in contact. (5) Water cannot be used in thermometer because of its higher freezing point and lower boiling point than other liquids . If water is used in a thermometer , it will start phase change at 0oC and 100oC and will not measure temperature , out of this range .
PLEASE READ CAREFULLY AND PLEASE MARK AS BRAINLIEST :)
Answer:

Explanation:
From the question we are told that
The electric filed is
Generally according to Gauss law
=> 
Given that the electric field is pointing downward , the equation become

Here
is the excess charge on the surface of the earth
is the surface area of the of the earth which is mathematically represented as

Where r is the radius of the earth which has a value 
substituting values


So

Here
s the permitivity of free space with value

substituting values


Weight = mass * gravity
420 = mass * 9.8
mass of Betty = 42.857 kg
Difference in height = 1 - 0.45 = 0.55 meters
Total energy = Kinetic energy + potential energy
At the highest point, the kinetic energy is zero while the potential energy is maximum, therefore, we can get the total energy as follows:
Total energy = 0 + mgh
Total energy = 42.857*9.8*0.55 = 231 Joules
At the lowest point, the potential energy is zero while the kinetic energy is maximum. Therefore:
Total energy = 0.5 * m * (v)^2 + 0
231 = 0.5 * (42.857) * (velocity)^2
(velocity)^2 = 10.78
velocity = 3.28 meters/sec