How Is Total Work Calculated for Two Connected Blocks with Friction?

AI Thread Summary
Total work for the 20 N block is calculated using the formula w = f · d, where f is the net force and d is the distance moved. The kinetic friction force is determined by f_k = μ_k · n, leading to a calculation of work done against friction. The user initially miscalculated the work as 0.75 J but later resolved the problem independently. Frustration was expressed over the lack of timely responses from the forum. The discussion highlights the importance of understanding friction in work calculations for connected blocks.
james brug
Messages
34
Reaction score
0

Homework Statement



Two blocks are connected by a very light string passing over a massless and frictionless pulley . The 20.0 N block moves 75.0 cm to the right and the 12.0 N block moves 75.0 cm downward.

Find the total work done on the 20 N block if \mu _s\;=(coeff. of static friction)=0.500 and \mu _k \;\;\;\;=(coeff. of kinetic friction)=0.325 between the table and the 20 N block.

Homework Equations


w=f\cdot d
f_k=\mu_k\cdot n
f_s\leq\mu_s\cdot n

The Attempt at a Solution


w=[7.5N-(.325)(20N)](.75m)=.75J--wrong.
 
Physics news on Phys.org
Never mind. I've solved it myself through some careful research and considerable effort. It is unfortunate that no one was able to answer this in time. Perhaps you people want some monetary compensation? Or maybe no one liked my problem. Not particularly hard, is 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

Why Does the Friction Force Not Match in the Two Block Problem?
Replies
15
Views
3K
Frictional force acting between 2 stacked blocks
Replies
2
Views
2K
Two blocks on a plane connected with a Rod
Replies
6
Views
2K
How Does Friction Affect the Acceleration and Tension in a Two-Block System?
Replies
9
Views
2K
Confused conceptually about work done with pulleys
Replies
8
Views
2K
Find work given a pulley and two weights
Replies
6
Views
4K
Why do I not get the same result when I use change in PE?
Replies
3
Views
2K
First post: work and energy problem
Replies
5
Views
2K
How Is Total Work Calculated for Blocks on a Pulley System with Friction?
Replies
1
Views
7K
Calculating Forces and Kinetic Friction for a System of Connected Blocks
Replies
12
Views
2K

Hot Threads

Recent Insights

Back
Top