Answer:

Explanation:
When teacher falls into the cliff then she shout for Help at the same time
so here we know that sound will go down and reflect back up
so here in 3 s distance traveled by the sound



now in the same time the distance that teacher will fall down is given as



now total distance traveled by teacher and sound in 3 s


this total distance must be equal to twice the height of the cliff


Answer:
8.57 Hz
Explanation:
From the question given above, the following data were obtained:
Wavelength (λ) = 3.5 m
Velocity (v) = 30 m/s
Frequency (f) =?
The velocity, wavelength and frequency of a wave are related according to the equation:
Velocity = wavelength × frequency
v = λ × f
With the above formula, we can simply obtain the frequency of the wave as follow:
Wavelength (λ) = 3.5 m
Velocity (v) = 30 m/s
Frequency (f) =?
v = λ × f
30 = 3.5 × f
Divide both side by 3.5
f = 30 / 3.5
f = 8.57 Hz
Thus, the frequency of the wave is 8.57 Hz
Answer:
8.9 g/cm^3
Explanation:
density = mass/volume
volume = length * width * height
volume = (8.4 cm)(5.5 cm)(4.6 cm)
volume = 212.52 cm^3
mass = 1896 g
density = (1896 g)/(212.52 cm^3)
density = 8.9 g/cm^3
In object in motion stays in motion; speed
Answer:
32000joule.
Explanation:
given
mass. (m)=160kg
speed (v)=20m/s
now
kinetic energy =1/2 (mv²)=1/2 ×{160×20²}=32000joule.