How Do You Calculate Tension and Work for a Sledge Pulled at an Angle?

  • Thread starter Thread starter cjknowland
  • Start date Start date
  • Tags Tags
    Force Friction
AI Thread Summary
To calculate the tension in the rope pulling a sledge at an angle, the normal force must be determined, which is affected by the angle of pull and the weight of the sledge. The key equation involves balancing forces, recognizing that the sledge moves at constant speed, indicating zero acceleration. The tension can be calculated using the formula T = mgμ / (cos(θ) + sin(θ)μ), where m is mass, g is gravitational acceleration, μ is the coefficient of friction, and θ is the angle of pull. Work done by the rope and mechanical energy lost due to friction can also be derived from these calculations. Understanding these relationships is crucial for solving the problem effectively.
cjknowland
Messages
6
Reaction score
0

Homework Statement




A sledge loaded with bricks has a total mass of 17.4 kg and is pulled at constant speed by a rope inclined at 19.2° above the horizontal. The sledge moves a distance of 20.0 m on a horizontal surface. The coefficient of kinetic friction between the sledge and surface is 0.500.

(a) What is the tension in the rope?

(b) How much work is done by the rope on the sledge?

(c) What is the mechanical energy lost due to friction?


Homework Equations





The Attempt at a Solution



I am having trouble finding the normal force with the pull at 19.2 degrees. If anyone could help in solving this problem it would be greatly appreciated.
 
Physics news on Phys.org
I believe the key is that the acceleration is zero but I do not know how to apply it...
 
F-fk=MA but in order to find fk, I need to use fk=(coefficient of friction)(normal force) but i do not know how to find the normal force with the information given.
 
okay I got an answer of 76.76... I don't know if its correct
 
Solving for T, I got 76.97 N

I'm willing to bet the discrepancy is rounding.
To be sure, I used
mg-Tsin(θ) = N
friction = (mg-Tsin(θ))μ
Tcos(θ)=friction = (mg-Tsin(θ))μ

T(cos(θ) + sin(θ)μ) = mgμ

so, T =mgμ/(cos(θ) + sin(θ)μ)
 
Last edited:
thank you so much =]
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

How to Determine the Work Done by the Rope on a Sledge?
Replies
5
Views
2K
My Mistake? Understanding Friction Force & Work Done on Snowy & Icy Surfaces
Replies
29
Views
2K
Condition satisified when the body does not slide
Replies
4
Views
1K
Solve Tension Problem: A Sledge w/ Bricks & Coefficient of Kinetic Friction
Replies
4
Views
2K
Pulling a sled across snow with a rope at an angle
Replies
8
Views
4K
MHB Solving Mechanics: Friction of Sledge on Slope
Replies
9
Views
1K
Force pulling on a string at an angle with a block at the other end
Replies
2
Views
1K
Pulling a sled, work, and tension
Replies
15
Views
15K
Why is the tension force equal to friction force
Replies
9
Views
7K
Calculating Tension of a Rope for a Moving Sledge on an Inclined Surface
Replies
5
Views
5K

Hot Threads

Recent Insights

Back
Top