Answer :
The gravitational force on a 50 kg box moving down a 60° inclined plane is found by using the component of gravitational force parallel to the plane's surface, which is calculated as 424 N, corresponding to answer choice (d).
The question asks about the gravitational force experienced by a box of mass 50 kg moving down a frictionless inclined plane. To determine this force, we should consider the gravitational force acting on the box in the direction parallel to the surface of the incline. This component of the gravitational force, known as the parallel force, can be calculated using the formula:
Fparallel = mg imes sin(\theta)
where:
• m is the mass of the box,
• g is the acceleration due to gravity (9.8 m/s²), and
• \theta is the angle of the incline.
Substituting the values given in the problem:
Fparallel = 50 kg imes 9.8 m/s² imes sin(60°)
Using the sine of 60°, which is approximately 0.866, we find:
Fparallel = 50 kg imes 9.8 m/s² imes 0.866 \approx 424 N
Therefore, the correct answer is (d) 424 N. This is the gravitational force acting on the box parallel to the plane surface.