Answer:
The number of bright fringes per unit width on the screen is,
Explanation:
If d is the separation between slits, D is the distance between the slit and the screen and
is the wavelength of the light. Let x is the number of bright fringes per unit width on the screen is given by :

is the wavelength
n is the order
If n = 1,

So, the the number of bright fringes per unit width on the screen is
. Hence, the correct option is (B).
The neutral pH is 7. Less than 7 indicates an acid and more than 7 indicates a base (up to 14).
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NaCl - it's a salt (we can't measure the pH)
H2O - it can be an acid but also a base (the pH it is almost neutral,meaning close to 7 )
HF - it is a strong acid
</span><span>
KOH
- it is a strong base (pH=14)
</span>
↓
He needs to use HF (Hydrogen fluoride) to decrease the pH.
Answer:1.5×10 to the power of 17(unit-Hertz/H)
Explanation:V=F×Wavelength
F=V/Wavelength=3×10 to power/2×10 to power of -9=1.5×10 to power of 17
Answer:
the frequency of this mode of vibration is 138.87 Hz
Explanation:
Given;
length of the copper wire, L = 1 m
mass per unit length of the copper wire, μ = 0.0014 kg/m
tension on the wire, T = 27 N
number of segments, n = 2
The frequency of this mode of vibration is calculated as;

Therefore, the frequency of this mode of vibration is 138.87 Hz
Answer:because the parachute is built so the wind will push up on it make the man/woman glide or fall slowly will a stone which has a lot of desentity
falls through the air faster do to is weight and shape .
Explanation: