Physics Answers

Calculation of Bohr's atomic model of velocity of electron in nth orbit.

Calculation based on Bohr's atomic model.

Radius of nth orbit

What is Bohr atomic model?

Why population inversion are necessary for lasing action.

Explain discovery of Deuterium.

A speck of dust has a mass of 1.0 x 10-18 kg and carries a charge equal to that of one electron.

Near to the Earth's surface it experiences a uniform downward electric field of strength

100 N C-1 and a uniform gravitational field of strength 9.8 N kg-1.

Draw a free-body force diagram for the speck of dust. Label the forces clearly.

Calculate the magnitude and direction of the resultant force on the speck of dust.

Explain Atomic Excitation with detail.

Explain Nuclear Motion with details.

The position of a SHO as a function of time is given by x = 7.1cos 7πt  + π 

                          3      6

where t is in seconds and x is in centimetres. Find:

a)               the period and frequency expressed as fractions                        

b)              the velocity at t = 2.5 (to 2 sig. fig.)                                            

If a simple harmonic oscillator has velocity function of:

v                =      100πAsin(100πt – 0.75π)   Find:

         i) an expression for displacement, x.    

         ii) an expression for acceleration, a.