<h3>Concave or diverging lens is needed correct the vision of a nearsighted person whose far point is 30.0 cm</h3>
<em><u>Solution:</u></em>
Nearsighted person will not be able to see the distant objects clearly
Now, we want the near sighted person to see the distant objects clearly
<em><u>The lens equation is given as:</u></em>
For distant vision, 
The image of 30 cm from eye will be 28.5 cm to left of spectacle lens
Therefore,
From lens equation,
The negative power -3.51 D denotes that a concave or diverging lens is needed
Answer:
2.5 m
Explanation:
Weight of billboard worker = 800 N
Number of ropes = 2
Length of scaffold = 4 m
Weight of scaffold = 500 N
Tension in rope = 550 N
The sum of the torques will be
The position of the person will be 2.5 m
Answer:
Active—A volcano is active if it is erupting, or may erupt soon. ...
Dormant—A dormant volcano is one that may have erupted before, but it is no longer erupting. ...
Extinct—An extinct volcano is not erupting and will never erupt again.
Explanation:
<u>The possible formulas for impulse are as follows:</u>
J = FΔt
J = mΔv
J = Δp
Answer: Option A, E and F
<u>Explanation:</u>
The quantity which explains the consequences of a overall force acting on an object (moving force) is known as impulse. It is symbolised as J. When the average overall force acting on an object than such products are formed and in given duration than the start fraction force over change in time end fraction J = FΔt.
The impulse-momentum theorem explains that the variation in momentum of an object is same as the impulse applied to it: J = Δp J = mΔv if mass is constant J = m dv + v dm if mass changes. Logically, the impulse-momentum theorem is equivalent to Newton second laws of motion which is also called as force law.
Answer:
Power will be 0.2023 watt
And when amplitude is halved then power will be 0.0505 watt
Explanation:
We have given mass of the Piano wire m = 2.60 gram = 0.0026 kg
Length of wire l = 84 cm = 0.84 m
So mass density 
Tension in the wire T = 25 N
Frequency f = 120 Hz
So angular frequency 
And amplitude A = 1.6 mm = 0.0016 m
We have to find the generated power
Power is given by 
From the relation we can see that power 
So if amplitude is halved then power will be 
times
So power will be equal to 
