Answer:
frequency = 1475.45 Hz
Explanation:
given data
frequency f1 = 1215 Hz,
frequency f2 = 1265 Hz
police car moving vp = 25.0 m/s
solution
speed of sound u = 343 m / s
speed of the other car = v
when the police car is stationary
the frequency the other car receives is
f2 = f1 ×
................1
and
the frequency the police car receives is
f2 = f1 ×
..................2
now from equation 1 and 2


v = 4.77 m/s
and
frequency the other car receives is
f2 = f1 ×
......................3
and
the frequency the police car receives is
f2 = f1 ×
.......................4
now we get
f2 = f1 ×
f2 =
f2 = 1475.45 Hz
Answer:
(E)56.0 m/s
Explanation:
Height =h=-160 m
Because the wallet moving in downward direction
Time=t=7 s
Final speed of wallet=v=0
We have to find the speed of helicopter ascending at the moment when the passenger let go of the wallet.

Where 
Substitute the values



Option (E) is true
The answer is a because tjhey do move at a molecular movemn
Answer:
F = 4.147 × 10^23
v = 1.31 × 10^4
Explanation:
Given the following :
mass of Jupiter (m1) = 1.9 × 10^27
Mass of sun (m2) = 1.99 × 10^30
Distance between sun and jupiter (r) = 7.8 × 10^11m
Gravitational force (F) :
(Gm1m2) / r^2
Where ; G = 6.673×10^-11 ( Gravitational constant)
F = [(6.673×10^-11) × (1.9 × 10^27) × (1.99 × 10^30)] / (7.8 × 10^11)^2
F = [25.231 × 10^(-11+27+30)] / (60.84 × 10^22)
F = (25.231 × 10^46) / (60.84 × 10^22)
F = 3.235 × 10^(46 - 22)
F = 0.4147 × 10^24
F = 4.147 × 10^23
Speed of Jupiter (v) :
v = √(Fr) / m1
v = √[(4.147 × 10^23) × (7.8 × 10^11) / (1.9 × 10^27)
v = √32.3466 × 10^(23+11) / 1.9 × 10^27
v = √32.3466× 10^34 / 1.9 × 10^27
v = √17. 023 × 10^34-27
v = √17.023 × 10^7
v = 13047.221
v = 1.31 × 10^4
Refrigerator was what is commonly used today. We do dry foods and salt cure but that is not done on a daily basis