7. A concave mirror forms on a screen an image of twice the linear dimensions of the object Objcct and screen are then moved until the image is three times the size of
the object. If the shift of the screen is 20cm, determine the shifts of the object and
the focal length of the mirror.

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000