Answer:
the lowest frequency f of the sound wave is 214.375 Hz
Explanation:
The computation of the lowest frequency f of the sound wave is shown below;
Length = L= 80 cm
= 0.8 m
V = 343 m/s (sound speed in air )
Now
V1 = n V ÷ 2 L
= 1 × 343 ÷ 2 × 0.8
V1 = 214.375 Hz
Hence, the lowest frequency f of the sound wave is 214.375 Hz
We simply applied the above formula so that the correct value could come
And, the same is to be considered
Answer:
It is independent of the path of the body and depends only on the starting and ending points.
Explanation:
In Physics we define a conservative force as a force that is independent of the path of the body and depends only on the starting and ending points.
For conservative forces we can write;
KEi + PEi = KEf +PEf
where;
KEi= initial kinetic energy
PEi= initial potential energy
KEf= final kinetic energy
PEf= final potential energy
This equation is known as the principle conservation of mechanical energy . It applies only to conservative forces where friction is negligible. The term KE + PE is also known as the total mechanical energy of the system.
Answer:
the correct answer is c) 23 g
Explanation:
The heat lost by the runner has two parts: the heat absorbed by sweat in evaporation and the heat given off by the body
Q_lost = - Q_absorbed
The latent heat is
Q_absorbed = m L
The heat given by the body
Q_lost = M 
ΔT
where m is the mass of sweat and M is the mass of the body
m L = M c_{e} ΔT
m = M c_{e} ΔT / L
let's replace
m = 90 3.500 1.8 / 2.42 10⁶
m = 0.2343 kg
reduced to grams
m = 0.2342 kg (1000g / 1kg)
m = 23.42 g
the correct answer is c) 23 g
Speed = Distance/ Time
Speed = 400 / 4
Speed = 100 km/hr.
100 km per hour.
Answer:
73 db
Explanation:
A single air conditioner is equivalent to 70 dB frequency. An extra air conditioning unit would therefore double the sound frequency. It does not, however, double the decibels to 140 dB. Instead, it adds only 3 dB to the 70 dB, making the total decibels of two air conditioning units equal to 73 db
Hence the correct option is b that is 73 db
