A = <0,1>
B = <-1,3>
then
A + B = < 0+-1 , 1+3 > = <-1, 4>
magnitude = sqrt( (-1)^2 + (4)^2 )
= sqrt( 1 + 16)
= sqrt(17)
We need to consider for this exercise the concept Drag Force and Torque. The equation of Drag force is

Where,
F_D = Drag Force
= Drag coefficient
A = Area
= Density
V = Velocity
Our values are given by,
(That is proper of a cone-shape)



Part A ) Replacing our values,


Part B ) To find the torque we apply the equation as follow,



I assuming they are not going to be very big just small enough for the car to get over the top and not go backwards. The coasting is all the momentum thy have to get over the hill and they don't have a lot of momentum. hope this helps ☺