A) determine all the forces on the block. Show all your work B) determin µk, show all your work . PLEASE HELP ?
1 Answer
Jun 6, 2018
Explanation:
- figure-1 shows the weight of the block on inclined plane. Notice that the weight vector is perpendicular to the earth's surface.
- Now;let's draw two lines that it is shown like figure-2 . we will use these lines to find vertical and horizontal components of the weight of block.
- the figure-3 shows the parallel component of the weight of block. We can calculate this vector's magnitude using
#G_x"=mg*sin alpha=0.25*9.81*sin 33=1.34N#
- the figure-4 shows the perpendicular component of the weight of block. We can calculate this vector's magnitude using
#G_x"=mg*cos alpha=0.25*9.81*cos 33=2.06N#
- Since the vector
#G_y # applies on the surface as perpendicularly , the surface reacts to the block(Newton's third law).#N=-G_y=-2.06N#
- The forces acting perpendicular to the frictional surfaces have an effect on the frictional force. Friction force is shown in orange color. It must be opposite to the block motion. We calculate the frictional force using the formula
#F_f = mu _k*N = mu_k *mg cos alpha.#
- Note that the magnitudes of the blue and orange vectors are equal because the block moves at a constant speed(because of the Newton's first law).
#mu_k*cancel(mg) cos alpha=cancel(mg) sin alpha" , "mu_k=(sin alpha)/(cos alpha)=tan alpha=tan 33=0.65#
