Given :
Initial speed of car A is 15 m/s and initial speed of car B is zero.
Final speed of car A is zero and final speed of car B is 10 m/s.
To Find :
What fraction of the initial kinetic energy is lost in the collision.
Solution :
Initial kinetic energy is :

Final kinetic energy is :

Now, fraction of initial kinetic energy loss is :

Therefore, fraction of initial kinetic energy loss in the collision is 1.25 .
Explanation:
F = 20N m= m1 a=10m/s²
m=m2 a=5m/s²
F = ma
<u>for the first one</u><u>:</u><u> </u>
f=m1 × a
20 = m1 ×10
20=10m1
m1=20/10
m1=2
<u>for</u><u> </u><u>the</u><u> </u><u>second</u><u> </u><u>one</u><u> </u><u>:</u>
f=m2×a
20=m2×5
m2= 20/5
m2= 4
since F=ma
F=(m1+m2) ×a
F =(4+2)×a
F =6×a
F=20(from the question above )
20=6×a
a=20/6
a=3.33
To solve this problem we will use the definition of the period in a simple pendulum, which warns that it is dependent on its length and gravity as follows:

Here,
L = Length
g = Acceleration due to gravity
We can realize that
is a constant so it is proportional to the square root of its length over its gravity,

Since the body is in constant free fall, that is, a point where gravity tends to be zero:

The value of the period will tend to infinity. This indicates that the pendulum will no longer oscillate because both the pendulum and the point to which it is attached are in free fall.
Answer:

Explanation:
given.
magnification(m) = 400 x
focal length (f_0)= 0.6 cm
distance between eyepiece and lens (L)= 16 cm
Near point (N) = 25 cm
focal length of the eyepiece (f_e)= ?
using equation





i don't know the anss , sorry.