Wind or gravitational pull. A wave is made by friction between wind and the water’s surface. Waves can also be made by the sun and moon’s gravitational pull on the earth.
The specific heat capacity of a substance is the amount of energy needed to change the temperature of 1 kg of the substance by 1 degree Celsius.
from rarefaction to rarefaction for a longitudinal wave
Answer:
The focal length is 16.86 cm and the distance of the man if he wants to form an upright image of his chin that is twice the chin's actual size is 8.43 cm.
Explanation:
Given that,
Object distance u=1.54 m =154 cm
Image distance v = 15.2 cm
Magnification = 2
We need to calculate the focal length
Using formula of mirror

Put the value into the formula



We need to calculate the focal length
Using formula of magnification

Put the value into the formula


Using formula of for focal length






Hence, The focal length is 16.86 cm and the distance of the man if he wants to form an upright image of his chin that is twice the chin's actual size is 8.43 cm.