An electric motor rotating a workshop grinding wheel at a rate of 239 rev/min is switched off. Assume constant angular deceleration of magnitude 2.11 rad/s 2 . Through how many revolutions does the wheel turn before it finally comes to rest

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

the answer is 100. i just did this lesson and got a 100% on it. : )

-fishtank