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
Answer:
Mass of the oil drop, 
Explanation:
Potential difference between the plates, V = 400 V
Separation between plates, d = 1.3 cm = 0.013 m
If the charge carried by the oil drop is that of six electrons, we need to find the mass of the oil drop. It can be calculated by equation electric force and the gravitational force as :


, e is the charge on electron
E is the electric field, 


So, the mass of the oil drop is
. Hence, this is the required solution.
ANSWER - (1) are constantly moving (2) have volume (3) have intermolecular forces (4) undergo perfectly elastic collisions (5) have an average kinetic energy proportional to the ideal gas’s absolute temperature
<span>AnalStage. </span>According to Freud, a<span>dults fixated in this area could feel constantly out
of control or could need to be in control all the time. Pleasure focus
is on the anus, which occurs when a child learns to control bladder and bowel
movements. Fixation in this area can be caused from struggles during potty
training.</span>