Answer:
(a) You can tell that have the same strength because they have attracted the same amount of paper clips.
(b) Iron is used in electromagnets because steel retained magnetic properties after the power was turned off, but in the iron, the paper clips dropped off right away.
Heat transferred - Work done = Internal Energy
Explanation:
- If there is more heat transfer than the work done, the energy difference is called internal energy
- The first law of thermodynamics equation is given as ΔU=Q−W where, ΔU = Internal energy; Q = Heat transfer; W = Work done
- Heat = transfer of thermal energy between two bodies at different temperatures
- Work = force used to transfer energy between a system and its surroundings
- The First Law of Thermodynamics states - energy can be converted from one form to another with the interaction of heat, work and internal energy
- Energy cannot be created nor destroyed
Answer:
It covers distance of 9.15 football fields in the said time.
Explanation:
We know that
Thus distance covered in blinking of eye =
Thus no of football fields=
1) Frequency: 
the energy of the photon absorbed must be equal to the ionization enegy of the atom, which is
The energy of a photon is given by
where 
is the Planck's constant. By using the energy written above and by re-arranging thsi formula, we can calculate the frequency of the photon:
2) Wavelength: 91.2 nm
The wavelength of the photon can be found from its frequency, by using the following relationship:
where 
is the speed of light and f is the frequency. Substituting the frequency, we find
