Walker, Halliday & Resnick — Force and Motion-I: Problem 40

40 A dated box of dates, of mass 4.50 kg, is sent sliding up a frictionless ramp at an angle of \(\theta\) to the horizontal. Figure 5-31 gives, as a function of time \(t\), the component \(v_x\) of the box's velocity along an \(x\) axis that extends directly up the ramp. What is the magnitude of the normal force on the box from the ramp?