A suitcase of weight mg = 450 is being pulled by a small strap across a level floor. The coefficient of kinetic friction between the suitcase and the floor =0.640
a) Find the optimal angle of the strap above the horizontal. (The optimal angle minimizes the force necessary to pull the suitcase at constant speed.)
5 answers
My answer is 32.6...is that right? If not please tell me how you did it...
Oh my answer is right... can someone tell me how to calculate the minimum tension in the strap needed to pull the suitcase at constant speed? My answer for the tension is 534N and I know it's wrong...
Please
well, if you are pulling at an angle of 32.6 deg...
for constant velocity, the horizontal force =friction force
friction force=(mg-upwardforce)mu
= (450-tension*sin32.4)mu
that has to equal horizontal force, or
horizontalforce= tension*cos32.4
set them equal
tension*cos32.4=450*mu-tension*sin32.4
tension= 450mu/(cosT-sinT)
solve for tension.
for constant velocity, the horizontal force =friction force
friction force=(mg-upwardforce)mu
= (450-tension*sin32.4)mu
that has to equal horizontal force, or
horizontalforce= tension*cos32.4
set them equal
tension*cos32.4=450*mu-tension*sin32.4
tension= 450mu/(cosT-sinT)
solve for tension.
How did you get the angle?
1 answer