Compute the maximum possible efficiency of heat operating between the temperature limits of 100°C and
400°C​

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 right answer is 0.3 meters per second

it is b. absorbs thermal energy