A real image 4 times the size of the object is formed by a concave mirror on a screen. Later both the object and the screen were shifted until the image formed is 10 times the size of the object. if the distance moved is 15cm, what is the focal length of the mirror? Please I need the full solution
ASAP

The answer would be a) -80of

Inner peace.. jk it's  a stable electron configuration

W= fd
where f is an applied force and d is the distance over which it is applied. when a parachuting skydiver is at constant velocity, he is experiencing "terminal velocity", the point at which his acceleration down is canceled out by air resistance. that means that the resisting force of the air is equal to his weight, but in the opposite direction. with this, we can solve for the work done by the force.
w = fd
w = (92.0)(9.81 m/s^2) (325)
w= 2.93 x 10^5 j
the value for work in this case is positive because it is pushing up on the skydiver, who has a downward force of gravity.
therefore the answer is 2.93 x 10^5 j