The driver of a car traveling at 17.7 m/s ap-
plies the brakes and undergoes a constant
deceleration of 1.38 m/s.
how many revolutions does each tire make
before the car comes to a stop, assuming that
the car does not skid and that the tires have
radii of 0.42 m?
answer in units of rev.

43 revolutions.

Explanation:

The time it takes for the car to stop is

The distance it travels in that time is

The number of revolutions that the tires make is then

The last calculation just asks the question "how many tire circumferences fit into d=113 meters?"

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