<h2>Book will hit the foot with force 21.8 N</h2>
Explanation:
The momentum of any object = m v
here m is the mass of body and v is its velocity
Thus momentum P = 3.2 x 1 = 3.2 kg-m
As the book is falling freely , so it will fall with and acceleration g
The force exerted by it is = m g
Thus force = 2.18 x 10 = 21.8 N
Answer:
-0.4D(maybe)
Explanation:
combined focal length (f)= 0.4m
D1 = 5D
Then f1= 1/D1
= 1/5 = 0.2 m
1/f=1/f1+1/f2
1/0.4=1/0.2+1/f2
f2= -5/2
D2=1/f2= -0.4D
I don't see an image. Sorry I couldn't help you
I think the answer is D but i could be wrong