theanswer is b.heart disease
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.
Explanation:
Let us assume that moment about the pin and then setting it equal to zero as the rod is in equilibrium is as follows.
Moment = Force × Leverage

= 0

Therefore, we can conclude that the force (
) in the cable by assuming that the origin of our coordinate system is at the rod’s center of mass is 935.11 N.