Answer:
* in a tube with both ends open
λ = 2L / n n = 1, 2, 3,…
* tube with one end open and the other closed.
λ = 4L / n n = (2n ’+ 1 )
Explanation:
When a sound wave enters a pipe, a resonance process occurs, whereby only some wavelengths can occur.
* in a tube with both ends open
in this case there are maximums at each end, so if the length of the had is L
λ = 2L 1st harmonic
λ = 2 L / 2 2nd harmonic
λ = 2L / 3
λ = 2L / n n = 1, 2, 3,…
* In the case of a tube with one end open and the other closed.
At the open end there is a belly and at the closed end a node
λ = 4L 1st harmonic
λ = 4L / 3 3rd harmonic
λ = 4L / 5
λ = 4L / n n = 1, 3, 5,… odd
n = (2n ’+ 1 ) where n’ are all integers
Answer:
d.
Explanation:
Since the dart's initial speed v at angle has both vertical and horizontal components v₀sinθ and v₀cosθ respectively, the vertical component of the speed continues to decrease until it hits the target. It's displacement ,s is gotten from
s = y - y₀ = (v₀sinθ)t - 1/2gt² where y₀ = 0 m
y - 0 = (v₀sinθ)t - 1/2gt²
y = (v₀sinθ)t - 1/2gt²
which is the parabolic equation for the displacement of the dart.
Note that the horizontal component of the dart's velocity does not change during its motion.
Since the target falls vertically, with initial velocity u = 0 (since it was stationary before the string cut), it's displacement ,s' is gotten from
s' = y - y₀' = ut - 1/2gt² where y₀' = initial height of target above the ground
= (0 m/s)t - 1/2gt²
= 0 - 1/2gt²
y - y₀' = - 1/2gt²
y = y₀' - 1/2gt²
which is the parabolic equation for the displacement of the target.
The equation for both the displacement of the dart and the target can only be gotten if we considered vertical motion. So, the displacement component of both the dart and target are both vertical.
So, the answer is d.
Answer:
D. The primary source, because it was written by the researcher
Explanation:
One should learn to trust the primary source more because it is the real work of the researcher.
A primary work defines the work of research from his or her experimental findings.
- The primary source presents experimental data and other subordinates ones to reach a conclusion as seen from the view of the researcher.
- A secondary source implies someone else documenting their own opinion about the primary experimental set up.
- This can get dicey in the sense that results can be twisted to serve other ulterior motives.
