4

After a check up, a person now has a far point of 100 cm, but with good near point vision. He needs to wear a new pair of correc

lakkis [162]

Answer:

so his far point according to this pair of glass is 200 cm

Explanation:

power of old pair of corrective glasses is given as

$P = -0.5 dioptre$

now we have

$f = \frac{1}{P}$

$f = -2 m$

$f = -200 cm$

now we know that for normal vision the maximum distance of vision is for infinite distance

so by lens formula we have

$\frac{1}{d_i} + \frac{1}{d_o} = \frac{1}{f}$

$\frac{1}{d_i} + 0 = \frac{1}{200}$

$d_i = 200 cm$

so his far point according to this pair of glass is 200 cm

7 0

3 years ago

Please answer the question below

scoundrel [369]

The correct answer is B.
In a velocity vs time graph, a line going up means an increase in velocity, or speed, which correlates to positive acceleration. Negative acceleration means slowing down.

6 0

3 years ago

Confirm if this is correct or not. If it isn't correct, please correct it.

kow [346]

Answer:

d = 421.83 m

Explanation:

It is given that,

Height, h = 396.9 m

Horizontal speed, v = 46.87 m/s

We need to find the distance traveled by the ball horizontally. Let t is the time taken by the ball. Using second equation of motion for vertical direction. So,

$396.9=0\times t+\dfrac{1}{2}\times 9.8 t^2\\\\t=9\ s$

Now d is the distance covered by the cannonball. So,

$d=vt\\\\d=46.87\times 9\\\\d=421.83\ m$

Hence, this is the required solution.

3 0

2 years ago

What is the approximate wavelength of a light whose first-order bright band forms a diffraction angle of 45.0° when it passes

sp2606 [1]

** Missing info: Lines per mm = 500 **

Ans: The wavelength is = λ = 1414.21 nm

Explanation:
The formula for diffraction grading is:

dsinθ = mλ --- (1)

Where
d = 1/lines-per-meter = (1/500)*10^-3 = 2 * 10^-6
m = order = 1
λ = wavelength
θ = 45°

Plug in the values in (1):
(1) => 2*10^-6*sin(45°) = (1)λ
=> λ = 1414.21 nm

7 0

3 years ago

An open organ pipe of length 0.47328 m and another pipe closed at one end of length 0.702821 m are sounded together. What beat f

sineoko [7]

Answer:

fb = 240.35 Hz

Explanation:

In order to calculate the beat frequency generated by the first modes of each, organ and tube, you use the following formulas for the fundamental frequencies.

Open tube:

$f=\frac{v_s}{2L}$ (1)