Inclined Plane Problem: How to Calculate Acceleration and Tension?

AI Thread Summary
The discussion focuses on solving an inclined plane problem involving two connected loads, where a 3kg load on a 30-degree incline is linked to a 2kg load via a frictionless pulley. The calculations for acceleration and tension reveal that the acceleration is -2.56 m/s², indicating the direction of motion. The tension in the cord is calculated to be 14.886 N for the inclined load and -3.1176 N for the hanging load, leading to a total tension of 11.7684 N. Participants confirm the correctness of the acceleration and clarify that only one equation is needed for tension due to the connection of the loads. The thread concludes with appreciation for the assistance received in solving the problem.
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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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