Here, we know, according to 3rd Equation of Kinematics,
v² - u² = 2as
Here, u = 0 [ Free fall ]
a = 9.8 m/s² [ constant value for the Earth system ]
s = 15 m
Substitute their values,
v² - 0² = 2 * 9.8 * 15
v² = 294
v = √294
v = 17.15 m/s
In short, Your Answer would be Option D
Hope this helps!
Because your brain cant handle all of the information.
The work required to stop the car is equal to the amount of kinetic energy that the car currently has. This is given by E=(1/2)mv^2. Since the energy is proportional to the square of the velocity, that factor will have the greatest influence on the work required to stop it.
