Answer:
-47 °C
Explanation:
Speed of sound in air at sea level is:
v = 331 m/s + 0.6 m/s/°C T
where T is the temperature in Celsius.
The speed of sound is also the frequency times the wavelength:
v = fλ
Therefore:
fλ = 331 m/s + 0.6 m/s/°C T
(658 Hz) (0.46 m) = 331 m/s + 0.6 m/s/°C T
302.68 m/s = 331 m/s + 0.6 m/s/°C T
-28.32 m/s = 0.6 m/s/°C T
T = -47.2 °C
Rounding to two significant figures, the temperature is -47 °C.
we know that
Power efficiency is defined as the ratio of the output power divided by the input power:
so

in this problem

Substitute in the formula above

%
therefore
the answer is
the efficient is
%
Answer:

Explanation:
m = Mass of bungee jumper = 55 kg
g = Acceleration due to gravity = 
h = Height at the bottom = 40 m
k = Spring constant
x = Displacement of bungee cord = 25 m
Applying the principle of conservation of energy to the system we have

The spring constant of the bungee cord is
.
Energy is conserved. If the ball reaches a height of 5.50 m, it has gained a certain amount of gravitational potential energy. That energy had to come from somewhere. From this fact, you can deduce the speed of the ball at the end of the impact with the racket.
<h3>What is
gravitational potential energy?</h3>
Gravitational energy or gravitational potential energy is the potential energy a huge item has corresponding to one more monstrous article because of gravity. It is the potential energy related with the gravitational field, which is delivered (changed over into active energy) when the articles fall towards one another. Gravitational potential energy increments when two articles are brought further apart. It is the potential energy related with the gravitational field, which is delivered (changed over into dynamic energy) when the items fall towards one another. Gravitational potential energy increments when two items are brought further separated.
Learn more about gravitational potential energy, visit
brainly.com/question/13978841
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Answer
given,
frequency from Police car= 1240 Hz
frequency of sound after return = 1275 Hz
Calculating the speed of the car = ?
Using Doppler's effect formula
Frequency received by the other car
..........(1)
u is the speed of sound = 340 m/s
v is the speed of the car
Frequency of the police car received

now, inserting the value of equation (1)


1.02822(340 - v) = 340 + v
2.02822 v = 340 x 0.028822
2.02822 v = 9.799
v = 4.83 m/s
hence, the speed of the car is equal to v = 4.83 m/s