A block of mass m is at rest on a plane inclined at an angle of 30 degrees with the horizontal. Which of the following statements about the force of

static friction is necessarily true? \mathrm{fs}=\mathrm{mg} \sin (30 \mathrm{deg}) \mathrm{fs}>\mathrm{mg} \mathrm{fs}>\mathrm{mg} \cos (30 \mathrm{deg}) \mathrm{fs}=\mathrm{mgcos}(30 \mathrm{deg})