Asked by Marie
Find the work done in pulling a 120 gram box in an incline plane, 150 cm long and 90 cm high if the coefficient of friction is 0.25.
Answers
Answered by
bobpursley
Your teacher is just too easy.
work done=netforce * distance
net force is work done against friction plus work done against gravity. In either case, it is force*distance*cosine of the angle between.
Gravity: downward force, distance is .9m, and the angle between is arctan90/150
work done on gravity: .120*g*.8cos(arctan 9/15)
you can use your calculator on that.
workdone on friction.
friction work= forcenormal*mu*distance
= mgCos arctan9/15*mu*.9*cos arctan 9/15
so grab your calculator and add.
work done=netforce * distance
net force is work done against friction plus work done against gravity. In either case, it is force*distance*cosine of the angle between.
Gravity: downward force, distance is .9m, and the angle between is arctan90/150
work done on gravity: .120*g*.8cos(arctan 9/15)
you can use your calculator on that.
workdone on friction.
friction work= forcenormal*mu*distance
= mgCos arctan9/15*mu*.9*cos arctan 9/15
so grab your calculator and add.