Respuesta :
The magnitude of the normal force is to be considered as the mg cos θ when the box of mass m is at rest.
What is magnitude?
In terms of physics, it refer to the maximum size where it should be extended also it defined the object direction. It is factor for vector and the scalar quantities.
When the box of mass m should be at rest so here the ramp should be an angle so here the weight should be perpendicular to the string.
hence, The magnitude of the normal force is to be considered as the mg cos θ when the box of mass m is at rest.
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