Some call it "air resistance", and others just call it "drag".
Answer:
Explanation:
For simple pendulum the formula is

Where T is time period , l is length and g is acceleration due to gravity .

n is frequency
Putting the values


l = 1.584 m
Velocity, direction, or both at the same time.
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 .