Answer:
42 m
Explanation:
= initial velocity of the car = 24 m/s
= final velocity of the car = 0 m/s
μ = coefficient of kinetic friction = 0.7
g = acceleration due to gravity = 9.8 m/s²
a = acceleration due to kinetic frictional force = - μg = - (0.7)(9.8) = - 6.86 m/s²
d = distance through which the car skids
Using the kinematics equation

Inserting the values

d = 42 m
If
and
are perpendicular, then their dot product is zero. This means

Solving for n is trivial; it follows that n = 3.
To solve this problem it is necessary to apply the trigonometric ratios of the given velocity components.
If we make a graph of the velocity vectors in their respective velocities according to the given description we will have something similar to the attached graph.
The angle could be obtained from the components of the opposite leg and the adjacent leg so that


The opposite leg value (y) is 40cm / s and the adjacent leg (x) is 30cm / s


Therefore the final direction that does the first ball is 36.87°
The answer is c
Distance/speed=time
Therefore 4000/500=8