f' = frequency observed by the police car after sound reflected from the vehicle and comes back to police car = 1250 Hz
f = frequency emitted by the police car = 1200 Hz
V = speed of sound = 340 m/s
v = speed of vehicle = ?
frequency observed by the police car is given as
f' = f (V + v)/(V - v)
inserting the values in the above equation
1250 = 1200 (340 + v)/(340 - v)
v = 6.9 m/s
To solve this problem we will apply the concepts related to the electric field such as the smelting of the Force and the load (In this case the force is equivalent to the weight). Later we will apply the ratio of the total charge as a function of the multiplication of the number of electrons and their individual charge.
Here,
m = mass
g = Acceleration due to gravity
Rearranging to find the charge,
Replacing,
Since the field is acting upwards the charge on the drop should be negative to balance it in air. The equation to find the number of electrons then is
Here,
n = Number of electrons
e = Charge of each electron
Replacing,
Therefore the number of electrons that reside on the drop is 
Answer:
Explanation:
if its squares count the squares els messure it i think
Answer:
doubled the initial value
Explanation:
Let the area of plates be A and the separation between them is d.
Let V be the potential difference of the battery.
The energy stored in the capacitor is given by
U = Q^2/2C ...(1)
Now the battery is disconnected, it means the charge is constant.
the separation between the plates is doubled.
The capacitance of the parallel plate capacitor is inversely proportional to the distance between the plates.
C' = C/2
the new energy stored
U' = Q^2 / 2C'
U' = Q^2/C = 2 U
The energy stored in the capacitor is doubled the initial amount.
A rotation is when the earth turns in a circle on it's axis. A revolution is the oblong path the the earth is constantly moving in around the sun. A revolution takes 365.25 days where as a rotation happens in 24 hours. <span />
