Answer:
36 m/s
Explanation:
The speed of wave is a product of wavelength and frequency, expressed as s=fw where f is frequency in Hz and w is wavelength. Wavelength is the distance between successive crests while frequency is also the reciprocal of time. Amplitude has no effect on the velocity of waves. Substituting frequency with 12 Hz and wavelength with 3 m then the speed will be
S=3*12=36 m/s
Therefore, the speed is 36 m/s
-- The boiling points of the first group are all at temperatures
that are way lower than a comfortable room.
. . . . . Nitrogen . . . -320° F
. . . . . Helium . . . . -452° F
. . . . . Neon . . . . . -411° F
The freezing points of the second group are all at temperatures
that are way higher than a comfortable room.
. . . . . Lithium. . . . . . 357° F
. . . . . Sodium . . . . . 208° F
. . . . . Potassium . . . 146 °F
Answer:
Please see below as the answer is self- explanatory.
Explanation:
- Any time that an object changes direction (from leftward to rightwward, or from upward to downward) the velocity must be zero just for one instant, when is on the verge of changing the direction.
- This is needed because velocity changes as a continuous function of time, so it needs to cross the t-axis when passing from positive to negative or vice versa.
- However, the claim that in the moment that velocity is zero, the acceleration is also zero, is false.
- Due to acceleration is the rate of change of velocity, and velocity is a vector, this means at any time there is a change of direction, there is an acceleration that is non-zero.
- For example, when an object that has been thrown upward, reaches to its maximum height, just one instant before starting to fall, the velocity becomes zero, but the acceleration (which causes the object to fall) is non-zero, due to it's the acceleration due to gravity.
B. 60 cm
All parallel light rays are bent through the focal point of a convex lens, so the rays from the flashlight 150 cm above the floor must go through the same point on the principal axis as the rays from the flashlight 120 cm above the floor. The location of the focal point does not change when the position of the object is moved either vertically or horizontally.
Hope this helps !
I = pressure amplitude given = 0.2 W/m²
dB = decibel reading
decibel reading from the pressure amplitude is given as
dB = 10 log₁₀ (I/10⁻¹²)
inserting the values in the above equation
dB = 10 log₁₀ (0.2/10⁻¹²)
dB = 10 log₁₀ (2 x 10⁻¹/10⁻¹²)
dB = 10 log₁₀ (2 x 10⁻¹.10¹²)
dB = 10 log₁₀ (2 x 10¹²⁻¹)
dB = 10 log₁₀ (2 x 10¹¹)
dB = 113.01 db
hence the decibel reading comes out to be 113.01 db
