Work done by Friction on an Inclined Plane

AI Thread Summary
The discussion revolves around calculating the work done by friction on a suitcase being pulled up an inclined plane. The suitcase has a mass of 17.1 kg, and the force applied is 146 N with a coefficient of kinetic friction of 0.257. An initial attempt to calculate the friction force incorrectly used the formula for static friction, leading to confusion about the work done. After realizing the need to consider the normal force's dependence on gravity and the incline's angle, the correct approach was acknowledged. The conversation highlights the importance of free body diagrams in resolving forces on inclined planes.
fajoler
Messages
11
Reaction score
1

Homework Statement



A luggage handler pulls a suitcase of mass 17.1 kg up a ramp inclined at an angle 24.0 above the horizontal by a force of magnitude 146 N that acts parallel to the ramp. The coefficient of kinetic friction between the ramp and the incline is 0.257. The suitcase travels a distance 3.90 m along the ramp.

What is the work done on the suitcase by the friction force?

Homework Equations



W = F o r = |F|*|r|*cos(theta)
Friction Force = uN

The Attempt at a Solution



Ok so I calculated that the Friction Force should equal umg since the direction of movement is along the incline rather than in the x direction. So Friction Force = 43.06806 N. If we multiply it by the change in distance, the Work done by friction should be -168 J, but this doesn't seem to be the correct answer. Anyone know where I may have screwed up?
 
Physics news on Phys.org
well force of friction is not \mu mg . set up a free body diagram first.
 
Oh wow... I'm sorry that was a stupid move on my part. For some reason I forgot that the normal force depends on gravity AND the direction of the gravitational force... Thanks so much I appreciate it!
 
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanged mass'

Thread 'A cylinder connected to a hanged mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Finding the work done by a block
Replies
4
Views
3K
Work Done by Friction & Gravity on Incline: Explained
Replies
7
Views
7K
Frictional force on an inclined plane
Replies
24
Views
5K
Inclined Plane Forces - with a twist
Replies
2
Views
1K
Determining Work Done by a Person on a Luggage
Replies
2
Views
1K
Coefficient of Friction question for a cart going down a wooden ramp
Replies
18
Views
3K
Calculating work on an inclined plane
Replies
6
Views
19K
Variable friction on an inclined plane and maximum velocity
Replies
33
Views
3K
Friction force on an inclined plane
Replies
3
Views
2K
Work Done on a Suitcase by Various Forces
Replies
2
Views
6K

Hot Threads

Recent Insights

Back
Top