Answer:
acceleration, a = 9.8 m/s²
Explanation:
'A ball is dropped from the top of a building' indicates that the initial velocity of the ball is zero.
u = 0 m/s
After 2 seconds, velocity of the ball is 19.6 m/s.
t = 2s, v = 19.6 m/s
Using
v = u + at
19.6 = 0 + 2a
a = 9.8 m/s²
Complete Question
The compete question is shown on the first uploaded question
Answer:
The speed is
Explanation:
From the question we are told that
The distance of separation is d = 4.00 m
The distance of the listener to the center between the speakers is I = 5.00 m
The change in the distance of the speaker is by 
The frequency of both speakers is 
Generally the distance of the listener to the first speaker is mathematically represented as
![L_1 = \sqrt{l^2 + [\frac{d}{2} ]^2}](https://tex.z-dn.net/?f=L_1%20%20%3D%20%20%5Csqrt%7Bl%5E2%20%2B%20%5B%5Cfrac%7Bd%7D%7B2%7D%20%5D%5E2%7D)
![L_1 = \sqrt{5^2 + [\frac{4}{2} ]^2}](https://tex.z-dn.net/?f=L_1%20%20%3D%20%20%5Csqrt%7B5%5E2%20%2B%20%5B%5Cfrac%7B4%7D%7B2%7D%20%5D%5E2%7D)

Generally the distance of the listener to second speaker at its new position is
![L_2 = \sqrt{l^2 + [\frac{d}{2} ]^2 + k}](https://tex.z-dn.net/?f=L_2%20%20%3D%20%20%5Csqrt%7Bl%5E2%20%2B%20%5B%5Cfrac%7Bd%7D%7B2%7D%20%5D%5E2%20%2B%20k%7D)
![L_2 = \sqrt{5^2 + [\frac{4}{2} ]^2 + 0.6}](https://tex.z-dn.net/?f=L_2%20%20%3D%20%20%5Csqrt%7B5%5E2%20%2B%20%5B%5Cfrac%7B4%7D%7B2%7D%20%5D%5E2%20%2B%200.6%7D)
Generally the path difference between the speakers is mathematically represented as

Here
is the wavelength which is mathematically represented as

=> 
=>
=>
Here n is the order of the maxima with value of n = 1 this because we are considering two adjacent waves
=>
=>
<span>1.5 minutes per rotation.
The formula for centripetal force is
A = v^2/r
where
A = acceleration
v = velocity
r = radius
So let's substitute the known values and solve for v. So
F = v^2/r
0.98 m/s^2 = v^2/200 m
196 m^2/s^2 = v^2
14 m/s = v
So we need a velocity of 14 m/s. Let's calculate how fast the station needs to spin.
Its circumference is 2*pi*r, so
C = 2 * 3.14159 * 200 m
C = 1256.636 m
And we need a velocity of 14 m/s, so
1256.636 m / 14 m/s = 89.75971429 s
Rounding to 2 significant digits gives us a rotational period of 90 seconds, or 1.5 minutes.</span>
Answer:
Smaller refractive power
Explanation:
The refractive power of an eye is the extent to which it can converge or diverge the light rays.
Near point is the the closest point for an eye such that when an object is placed at that point the image it forms is sharp and clearly visible to the eye.
A the person ages, the ciliary muscles of the eyes weakens and as a result the lens contracts and the formation of the image takes place behind the retina instead of forming at the retina.
Thus the near point also increases and the refractive power becomes smaller.