بسم الله الرحمن الرحيم
السلام عليكم ورحمة الله وبركاته
Question 1
First you have to find the acceleration
a = (vf² - vi²) / 2d
Where ,
vf² is the final velocity which is ZERO
vi² is the drifting speed
Now you get this equation
a = -vi²/2d
Second determine the force
F = m*a
m is the mass which = W * g , where W is the weight & g is the gravity acceleration which is 9.8 m/s²
a is the acceleration found in the first step
Just plug in the values and it is done.
you will have finally an equation like this
F = -(W/g) (vi²/2d)