A circular coil of 160 turns and radius 4.50 cm is placed inside and coaxial to a solenoid with 350 turns/m. If the current in the solenoid is represented by the equation I = a(1 − e−bt) where a = 21.0 A and b = 1.85 s−1, determine the magnitude of the induced emf in the coil when t = 1.50 s.

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