A runaway train car that has a mass of 15,000 kg travels at a speed of 5.4 m/s down a track. Compute the time required for a force of 1500 N to bring the car to rest.

The 1500 N force would need to act in the direction opposite the train car's movement, so if we take the current direction it's moving in to be positive, we have by Newton's second law

-1500 N = (15,000 kg) a   →   a = -0.10 m/s²

If t is the time it takes for the train to come to rest, then

-0.10 m/s² = (0 - 5.4 m/s) / t

t = (5.4 m/s) / (0.10 m/s²)   →   t = 54 s

i think the answer would be reserve.

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