An unbanked (flat) curve of radius 150 m is rated for a maximum speed of 39. 5 m/s. At what maximum speed, in m/s, should a flat curve with radius of 69. 0 m be rated.

before we can answer, we have to see the choices that are printed there with the question.   that's the only way we can point you to the correct one.

i would think it's food chain

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