Need to draw it first.....
but there is no option here to draw .. why?
anyway , here the car is going with a uniform velocity..
so the acceleration of the car=0, a=0
so resistive force on the car=component along the inclined plane of the weight of the car=mg*cos(90-15)=960*9.8*cos 75=?
Anything that doesnt have a change in magnitude or direction is something thats not accelerating. so, for example, a car moving at a constant speed of 5mph on a flat road is an example of an object moving but not accelerating
Answer:
The free body diagram of John is shown in the attached figure (in the FBD john's mass is supposed to be concentrated at his center of mass and FBD is made of center of mass)
b) As shown in the FBD the ground reaction forces are:
i) In X direction 
ii) In Y direction 
c) The respective accelerations in x and y direction's is calculated by newton's second law as indicated under

Answer:
245N
Explanation:
We just need to multiply the force the man pulls the wagon by the cosine of the angle with the ground.
F = 330N * cos(42°) = 245.2N