A magnet has a South Pole and a North Pole. South Pole and South Pole can't connect to her other, same as North and North. The same poles push each other away.
South Pole and North Pole connect.
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

Force = mass * acceleration = 1500kg * 8m/s²
Answer:
work done is -150 kJ
Explanation:
given data
volume v1 = 2 m³
pressure p1 = 100 kPa
pressure p2 = 200 kPa
internal energy = 10 kJ
heat is transferred = 150 kJ
solution
we know from 1st law of thermodynamic is
Q = du +W ............1
put here value and we get
-140 = 10 + W
W = -150 kJ
as here work done is -ve so we can say work is being done on system
30 grams of radioactive isotope have passed.