An electron moves in a circular path perpendicular to a magnetic field of magnitude 0.275 t. if the kinetic energy of the electron is 4.90 10-19 j, find the speed of the electron and the radius of the circular path.

Radius,

Explanation:

It is given that,

Magnetic field, B = 0.275 T

Kinetic energy of the electron,

Kinetic energy is given by :

v = 1037749.04 m/s

The centripetal force is balanced by the magnetic force as :

So, the radius of the circular path is . Hence, this is the required solution.

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.