A block of mass 1.5 kg is at rest on a rough surface which is inclined at 20° to the horizontal as shown.

a. Draw a free-body diagram showing the three forces acting on the block.
b. Calculate the component of the weight that acts down the slope.
c. Use your answer to part b to determine the force of friction that acts on the block.
d. If the angle of the surface is actually measured as 19° and 21° determine the absolute uncertainty in this angle and the uncertainty this produces in the value for part b.
e. Determine the normal contact force between the block and the surface.

Transcribed Image Text:

20° Figure 4.30