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:
2.5m/s^2
Explanation:
Step one:
given
distance = 20meters
time = 2 seconds
initial velocity u= 0m/s
let us solve for the final velocity
velocity = distance/time
velocity= 20/2
velocity= 10m/s
divide both sides by 40
Answer:the pressure depends on gas and it will be half as much underwater
Explanation:
Water pressure increases with the depth of the water. This is because the weight of the column of water above the object increases. But a large, shallow pond may have more water in it than a small, deep pond.
This is due to an increase in hydrostatic pressure, the force per unit area exerted by a liquid on an object. The deeper you go under the sea, the greater the pressure of the water pushing down on you. For every 33 feet (10.06 meters) you go down, the pressure increases by one atmosphere .
Answer:
1.97×10⁻²¹ J
Explanation:
Use ideal gas law to find temperature.
PV = nRT
(9 atm) (9 L) = (83.3 mol) (0.0821 L·atm/mol/K) T
T = 11.9 K
The average kinetic energy per atom is:
KE = 3/2 kT
KE = 3/2 (1.38×10⁻²³ J/K) (11.9 K)
KE = 2.46×10⁻²² J
For a mass of 5.34×10⁻²⁶ kg, the kinetic energy is:
KE = (5.34×10⁻²⁶ kg) (1 mol / 0.004 kg) (6.02×10²³ atom/mol) (2.46×10⁻²² J)
KE = 1.97×10⁻²¹ J
