Answer:
Image distance is -52.5 cm
Image is virtual and forms on the same side of the lens and upright image is formed.
Explanation:
u = Object distance
v = Image distance
f = Focal length = 35
m = Magnification = 2.5
![m=-\frac{v}{u}\\\Rightarrow 2.5=-\frac{v}{u}\\\Rightarrow v=-2.5 u](https://tex.z-dn.net/?f=m%3D-%5Cfrac%7Bv%7D%7Bu%7D%5C%5C%5CRightarrow%202.5%3D-%5Cfrac%7Bv%7D%7Bu%7D%5C%5C%5CRightarrow%20v%3D-2.5%20u)
Lens equation
![\frac{1}{f}=\frac{1}{u}+\frac{1}{v}\\\Rightarrow \frac{1}{35}=\frac{1}{u}+\frac{1}{-2.5u}\\\Rightarrow \frac{1}{35}=\frac{3}{5u}\\\Rightarrow u=21\ cm](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bf%7D%3D%5Cfrac%7B1%7D%7Bu%7D%2B%5Cfrac%7B1%7D%7Bv%7D%5C%5C%5CRightarrow%20%5Cfrac%7B1%7D%7B35%7D%3D%5Cfrac%7B1%7D%7Bu%7D%2B%5Cfrac%7B1%7D%7B-2.5u%7D%5C%5C%5CRightarrow%20%5Cfrac%7B1%7D%7B35%7D%3D%5Cfrac%7B3%7D%7B5u%7D%5C%5C%5CRightarrow%20u%3D21%5C%20cm)
![v=-2.5\times 21=-52.5\ cm](https://tex.z-dn.net/?f=v%3D-2.5%5Ctimes%2021%3D-52.5%5C%20cm)
Image distance is -52.5 cm
Image is virtual and forms on the same side of the lens and upright image is formed.
Answer:
20cm
Explanation:
A convex lens has a positive focal length and the object placed in front of it produce both virtual and real image <em>(image distance can be negative or positive depending on the nature of the image</em>).
According to the lens equation
where;
f is the focal length of the lens
u is the object distance
v is the image distance
If the magnification is - 0.6
mag = v/u = -0.5
v = -0.5u
since v = 10cm
10 = -0.5u
u = -10/0.5
u =-20 cm
Substitute u = -20cm ( due to negative magnification)and v = 10cm into the lens formula to get the focal length f
![\frac{1}{f} = \frac{1}{u} + \frac{1}{v}\\\frac{1}{f} = \frac{1}{-20} + \frac{1}{10}\\\frac{1}{f} = \frac{1}{-20} + \frac{1}{10}\\\frac{1}{f} = \frac{-1+2}{20} \\\frac{1}{f} = \frac{1}{20} \\cross \ multiply\\f = 20\\f = 20 cm](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bf%7D%20%3D%20%5Cfrac%7B1%7D%7Bu%7D%20%2B%20%5Cfrac%7B1%7D%7Bv%7D%5C%5C%5Cfrac%7B1%7D%7Bf%7D%20%3D%20%5Cfrac%7B1%7D%7B-20%7D%20%2B%20%5Cfrac%7B1%7D%7B10%7D%5C%5C%5Cfrac%7B1%7D%7Bf%7D%20%3D%20%5Cfrac%7B1%7D%7B-20%7D%20%2B%20%5Cfrac%7B1%7D%7B10%7D%5C%5C%5Cfrac%7B1%7D%7Bf%7D%20%3D%20%5Cfrac%7B-1%2B2%7D%7B20%7D%20%5C%5C%5Cfrac%7B1%7D%7Bf%7D%20%3D%20%5Cfrac%7B1%7D%7B20%7D%20%5C%5Ccross%20%5C%20multiply%5C%5Cf%20%3D%2020%5C%5Cf%20%3D%2020%20cm)
Hence the focal length of the convex lens is 20cm
That's efficiency. There's no law that it must be stated in percent.
Magma<span> is composed of molten rock and is stored in the Earth's crust. </span>Lava<span> is </span>magma<span> that reaches the surface of our planet through a volcano vent. </span>Lava<span>flow, Hawai.</span>
Answer:
60000 J
Explanation:
Assuming the force is applied parallel to the displacement of the elephant, the work done to move it across the floor is
![W=Fd](https://tex.z-dn.net/?f=W%3DFd)
where
F = 2000 N is the force applied
d = 30 m is the displacement of the elephant
Substituting the numbers into the formula, we find
![W=(2000 N)(30 m)=60,000 J](https://tex.z-dn.net/?f=W%3D%282000%20N%29%2830%20m%29%3D60%2C000%20J)