Answer:
(B) +18 cm
Explanation:
Given that the distance of the object is infinity.
And the image is formed at a distance of 18 cm, means
.
Now as we know that the mirror formula is,
![\frac{1}{f} =\frac{1}{u} +\frac{1}{v}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bf%7D%20%3D%5Cfrac%7B1%7D%7Bu%7D%20%2B%5Cfrac%7B1%7D%7Bv%7D)
Now put the values of u and v
![\frac{1}{f} =\frac{1}{\infty } +\frac{1}{18}\\\frac{1}{f}=0+\frac{1}{18}\\f=18 cm](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bf%7D%20%3D%5Cfrac%7B1%7D%7B%5Cinfty%20%7D%20%2B%5Cfrac%7B1%7D%7B18%7D%5C%5C%5Cfrac%7B1%7D%7Bf%7D%3D0%2B%5Cfrac%7B1%7D%7B18%7D%5C%5Cf%3D18%20cm)
Therefore the focal length of the mirror is +18 cm.
B) The velocity of a car reduced from 50 km/h to 35 km/h over one minute. <span>B) The velocity of a car reduced from 50 km/h to 35 km/h over one minute. </span>
Answer:
Explanation:
The human body utilizes the effect evaporation for cooling. Hence the water on the body surface make the skin to experience chilly as the wind blows to evaporate it. As the latent heat of vaporization is extracted from the body, it is cooler in the process. This is the same reason why perspiration cools the body as the sweat evaporate from the surface of the skin.
Answer:
Crystallization is defined as a process by which a chemical is converted from a liquid solution into a solid crystalline state.