Answer:
563.86 N
Explanation:
We know the buoyant force F = weight of air displaced by the balloon.
F = ρgV where ρ = density of air = 1.29 kg/m³, g = acceleration due to gravity = 9.8 m/s² and V = volume of balloon = 4πr/3 (since it is a sphere) where r = radius of balloon = 2.20 m
So, F = ρgV = ρg4πr³/3
substituting the values of the variables into the equation, we have
F = 1.29 kg/m³ × 9.8 m/s² × 4π × (2.20 m)³/3
= 1691.58 N/3
= 563.86 N
Answer:
A. 
.
Explanation:
By definition of Electric Capacitance, the capacitance of the system (
), in farads, is described by the following formula:
(1)
Where:
- Electric charge, in coulombs.
- Voltage, in volts.
If we know that 
and 
, then the capacitance of the system is:
The correct answer is A.
Answer:
Explanation:
A ) The spheres are non conducting , charge will not move on the surface so neutralization of charge by + ve and - ve charge is not possible. Charges will remain intact on them . The electric field inside them will be zero . Electric field outside shell will not be spherically symmetrical . Lines of force will emanate from the surface of positively charged shell outwardly oriented and end at negatively charged shell .
B )
distance between the centres of spherical shell
= 2 a
potential energy of charges
= k q₁ x q₂ / R
= k x - Q x Q / ( 2a )
= - k Q²/ 2a
So work needed to separate them to infinity will be equal to
= k Q²/ 2a
