Answer to Question #139935 in Classical Mechanics for Brendan Kirck

Question

What is the magnitude of force required to pull a block of massm= 100kgup the incline of 32 degrees with constant speed?

Answer 1

$F_{gravitational}= mass\times gravity.$

$= 100\times 9.8= 980N$

$F_{parrallel}=mg\sin \theta= 980\sin(30\degree)= 460N$

$F_{perpendicular}=mg\cos \theta= 980 \cos(30\degree)= 852.6N$

The forces directed perpendicular to the incline balance each other. Thus F_norm is equal to F_{perpendicular}.

$F_{Norm}= 852.6N$

There is no other force parallel to the incline to counteract the parallel component of gravity. Thus, the net force is equal to the F_parallel value.

Thus $F_{Net}= 460N$