The mass number of a nucleus (except Hydrogen) is: number of protons + number of neutrons.
A=Z+N
A=mass number=protons + neutrons.
Z=atomic number=number of protons.
N=number of neutrons.
In the case of Hydrogen it depends of isotope of Hydrogen .
the hydrogen has three isotopes,
protium : A=Z, because N=0
deuterium: A=Z+N; N=1
tritium: A=Z+N; N=2
Solution:
Mass of liquid water and water vapor in the insulated tank initially = 1.4 kg
Temperature = 200 °C
And 25% of the volume by liquid water is steam.
State 1



(taking the value of
and
at 200°C )

Now quality of vapor


Internal energy at state 1 can be found out by


= 856.54 kJ/kg
After heating with the resistor for 20 minutes, at state 2, the tank contains saturated water vapor 
Tank is rigid, so volume of tank is constant.



Now interpolate the value to get temperature at state 2 with specific volume value to get final temperature

= 369.11° C
Internal energy at state 2

Now power rating of the resistor


= 1.51 kW
Answer:
7350 J
Explanation:
Gravitational Potential Energy: This is defined as the energy possessed by a body due to it's position in the gravitational field. The S.I unit is Joules(J).
Applying,
E.p = mgh..................... Equation 1
Where E.p = Gravitational potential Energy, m = mass of the object, h = height of the object above the surface of the earth, g = acceleration due to gravity.
Given: m = 2.5 kg, h = 300 m
Constant: g = 9.8 m/s²
Substitute these values into equation 1
E.p = 2.5(300)(9.8)
E.p = 7350 J.
The first collision because a greater amount of momentum must be taken and used in order to push the cart back, giving it a greater mass and impulse
Answer: a) 11.76 m/s b) 7.056 m
Explanation:
The described situation is as follows:
An object is dropped from the top of a tower and when measuring the time it takes to reach the ground that turns out to be 0.02 minutes.
This situation is related to free fall, this also means we have constant acceleration, hence the equations we will use are:
(1)
(2)
Where:
Is the final velocity of the object
Is the initial velocity of the object (it was dropped)
is the acceleration due gravity
is the height of the tower
is the time it takes to the object to reach the ground
b) Begining with (1):
(3)
(4)
(5) This is the final velocity of the object
a) Substituting (5) in (2):
(6)
Clearing
:
(7)
(8) This is the height of the tower