Inclined Plane Problem: How to Calculate Acceleration and Tension?

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Homework Help Overview

The problem involves a 3kg load on an inclined plane at a 30-degree angle, connected by a cord over a frictionless pulley to a 2kg load. The original poster seeks to find the acceleration of each load and the tension in the cord.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • The original poster attempts to apply Newton's laws to analyze forces acting on both loads, including normal force and friction. Some participants question the correctness of the tension values calculated by the original poster, while others confirm the acceleration result.

Discussion Status

Some participants have provided feedback on the calculations, confirming the acceleration as correct. There is ongoing clarification regarding the tension in the cord, with participants discussing the relationship between the tensions in the system.

Contextual Notes

The original poster expresses uncertainty about the correctness of their answers and seeks validation of their approach. There is an indication that the loads are connected by a single cord, which may influence the tension calculations.

haengbon
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Homework Statement



A 3kg load on an inclined plane of angel 30 degrees is connected by a cord over a frictionless pulley to a second load which has a mass of 2 kg. Find the:

a) Acceleration of each load
b) tension of each chord


Homework Equations



none?


The Attempt at a Solution



block A / box on inclined plane

\sumFy= 0
-Wycos30\circ + NF= 0
-30cos30 + NF = 0
-25.98 + NF = 0
-25.98 = NF
NF = 25.98

f=\mu NF
f= 0.3 (25.98)
f= 7.794

\sumFx= ma
Wxsin30\circ - T - f = ma
15 - T - 7.794 = ma
15 - 7.794 - T = (3)(a)
-T = 3a - 7.206
T = 7.206 - 3a

block b

\sumFx= ma
T-W = ma
T - (2)(10) = (2)a
T - 20 = 2a
T= 2a+20

T=T
2a+20 = 7.206 - 3a
2a+3a = 7.206 - 20
5a = -12.794
a = - 2.56 m/s2

T1=7.206 - 3a
T= 7.206- 3(-2.56)
T= 14.886 N

T2= 2a+20
T= 2(-2.56) + 20
T= -3.1176 N

T2+T1 = TotalT
14.886 + (-3.1176) = TotalT
TotalT= 11.7684 N

I'm not sure if I got the right answer :( someone help?
 
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Loads are connected by a single cord. So T1 = T2 = T.
 
rl.bhat said:
Loads are connected by a single cord. So T1 = T2 = T.

so the tensions I got are incorrect then? :frown:
may I ask if the acceleration is correct?
 
Your acceleration is correct.
 
rl.bhat said:
Your acceleration is correct.

thank you ! :) so I only need to use one equation for my tension, and that's the answer? thank you very much again :) I really appreciate it ^^
 

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