# Find the work done by the force of friction on the flight bag.A flight attendant pulls her 74.2 N flight bag a distance of 324m along a level airport floor at a constant velocity. The force she...

Find the work done by the force of friction on the flight bag.

A flight attendant pulls her 74.2 N flight bag a distance of 324m along a level airport floor at a constant velocity. The force she exerts is 37.9 N at an angle of 55.2 degrees above the horizontal.

neela | High School Teacher | (Level 3) Valedictorian

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The force of friction is a force which is equal in magnitude but opposite in direction to the pulling component of the force along the floor.

The applied force =37.9N

Therefore the pulling component of the force = 37.9N cos55.2.

Thefrefore, the frictional force  is also equal in magnitude , which is 37.9N cos55.2

Threfore, the work done by the frictional force = (37.9 cos55.2)N*324m = 7008.1343 Nm = 7008.1343 J

krishna-agrawala | College Teacher | (Level 3) Valedictorian

Posted on

Given pulling force = f1 = 37.9 N

Angle of application of force = A = 55.2 degrees

Distance moved = 324 m

Other data given in the question is not required for finding the answer.

The pulling force is used partially reduce the effect of gravitational by pushing the bag up and there by reduce the friction, and partially to overcome the kinetic friction.

Thus the frictional force used to overcome kinetic friction (f) is equal to the horizontal component of pulling force applied.

The result is that a force f is applied and a displacement of s is obtained.

Therefore:

f = f1*Cos A = 37.9*Cos 55.2 = 37.9*0.5707 = 21.6295 N

work done = f*s = 21.6295*324 = 7007.9677 J