As a 1850 kg car is traveling down a road, it experiences a force of friction of 121 N and a force of air resistance if 186N. If the engine is not applying any force, what is the acceleration of the car

  -0.166 m/s²

Explanation:

F = Ma

a = F/M = (121 N +186 N)/(1850 kg) = 0.166 m/s²

The acceleration of 0.166 m/s² is in the direction opposite to the direction of travel, so might be considered to be negative.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards