Answer:
1.11 dioptre
Explanation:
= Distance of the image = - (125 - 2) = - 123 cm
= Distance of the object = 54 - 2 = 52 cm
= Focal length of the lens
Using the equation


cm
Power of the lens is given as


Dioptre
Answer:
u= 20.09 m/s
Explanation:
Given that
m = 0.02 kg
M= 2 kg
h= 0.2 m
Lets take initial speed of bullet = u m/s
The final speed of the system will be zero.
From energy conservation
1/2 m u²+ 0 = 0+ (m+M) g h
m u²=2 (m+M) g h
By putting the values
0.02 x u² = 2 (0.02+2) x 10 x 0.2 ( take g=10 m/s²)
u= 20.09 m/s