An electron in a TV CRT moves with a speed of 6.10 ✕ 107 m/s, in a direction perpendicular to the Earth's field, which has a strength of 5.00 ✕ 10−5 T. (a) What strength electric field (in kV/m) must be applied perpendicular to the Earth's field to make the electron move in a straight line?

The strength of the electric field is 3.05 kV/m

Explanation:

Given;

speed of electron, v = 6.10 ✕ 10⁷ m/s

strength of magnetic field, B = 5.00 ✕ 10⁻⁵ T

Electric force on the electron, F = Eq

Magnetic force on the electron, F = qvB

Eq =  qvB

E = vB

Where;

E is the electric field strength

v is the velocity of the electron

B is the magnetic field strength

E = vB = 6.10 x 10⁷ x 5.00 x 10⁻⁵

E = 3050 V/m = 3.05 kV/m

Therefore, the strength of the electric field is 3.05 kV/m

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.