It's equal to d external atmospheric pressure
Answer:
Explanation:
We shall find electric field at origin due to two given charges sitting on the either side of origin .
Total field will add up due to their same direction .
Field due to a charge Q
= 9 x 10⁹ x Q / R² ; R is distance of point , Q is charge
Field due to first charge
= 9 x 10⁹ x 40 x 10⁻³ / 2² x 10⁻⁴
= 90 x 10¹⁰ N/C
Field due to second charge
= 9 x 10⁹ x 50 x 10⁻³ / 2² x 10⁻⁴
= 112.5 x 10¹⁰ N/C
Total field
= 202.5 x 10¹⁰ N/C
Force on given charge at origin
= charge x field
= 4 x 10⁻³ x 202.5 x 10¹⁰
= 810 x 10⁷ N .
Here, F = m * a
F = m * v/t
Here, m = 81 Kg
v = 22 m/s
t = 1,4 s
Substitute their values,
F = 81 * 22/1.4
F = 81 * 15.71
F = 1273 N
So, Closest value from your options is 1300 N
In short, Your Answer would be Option B
Hope this helps!
B. number of oscillations in a given period of time.