Answer:
The Answer is D!
Explanation:
I checked it on Khan Academy.
Answer:
The answer is "
"
Explanation:

velocity of car | respect to car :

Answer:
8.89288275 m/s
Explanation:
F = Tension = 54 N
= Linear density of string = 5.2 g/m
A = Amplitude = 2.5 cm
Wave velocity is given by

Frequency is given by

Angular frequency is given by

Maximum velocity of a particle is given by

The maximum velocity of a particle on the string is 8.89288275 m/s
Wave speed = (wavelength) x (frequency)
= (1.5 m) x (500 / sec)
= 750 m/s .
Answer:
electrons
Explanation:
The magnitude of the electric field outside an electrically charged sphere is given by the equation

where
k is the Coulomb's constant
Q is the charge stored on the sphere
r is the distance (from the centre of the sphere) at which the field is calculated
In this problem, the cloud is assumed to be a charged sphere, so we have:
is the maximum electric field strength tolerated by the air before breakdown occurs
is the radius of the sphere
Re-arranging the equation for Q, we find the maximum charge that can be stored on the cloud:

Assuming that the cloud is negatively charged, then

And since the charge of one electron is

The number of excess electrons on the cloud is
