Tina is training for a biathlon. to train for the running portion of the race, she runs 9 miles each day over the same course. the first 4 miles of the course is on level ground, while the last 5 miles is downhill. she runs 2 miles per hour slower on level ground than she runs downhill. if the complete course takes 1 hour, how fast does she run on the downhill part of the course?

what is the actual question though?

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