Incline with friction and two blocks

In summary, the coefficient of kinetic friction between the blocks is 1/6 and the block accelerated down the ramp with a force of -3.7 m/s2. The tension in the string is mgsin(theta).
  • #1
SakuRERE
68
5

Homework Statement



The coefficient of kinetic friction between the block of mass m1 = 2.5 kg and the plane in Fig. 6 below is 1/6. Find (a) the acceleration of the block and (b) the tension in the string. Take g = 10 m/s2.
upload_2018-10-15_2-3-47.png


Homework Equations


Fnet=ma

The Attempt at a Solution


please i don't know what is the mistake here. the answer should be: a=2m/s^2 .
by the way i am assuming that the orange block is accelerating to the left down across the incline and so the green block up
this is my attempt :
upload_2018-10-15_2-5-11.png
 

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  • #2
i
SakuRERE said:

Homework Statement



The coefficient of kinetic friction between the block of mass m1 = 2.5 kg and the plane in Fig. 6 below is 1/6. Find (a) the acceleration of the block and (b) the tension in the string. Take g = 10 m/s2.
View attachment 232186

Homework Equations


Fnet=ma

The Attempt at a Solution


please i don't know what is the mistake here. the answer should be: a=2m/s^2 .
by the way i am assuming that the orange block is accelerating to the left down across the incline and so the green block up
this is my attempt :
View attachment 232187
i got a=-3.7 m/s^2
 
  • #3
I would change the sign of the tension force and the weight (mgsin(theta)) of block 1. Usually "up" the ramp is defined as positive.
 
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  • #4
osilmag said:
I would change the sign of the tension force and the weight (mgsin(theta)) of block 1. Usually "up" the ramp is defined as positive.
do you mean that the system will move up right? like hanging block would go down
 
  • #5
SakuRERE said:
do you mean that the system will move up right? like hanging block would go down

Compare the force of gravity on block 2 to that on block 1 when block 1 is on the ramp. Block 2 should go down.
 
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  • #6
osilmag said:
Compare the force of gravity on block 2 to that on block 1 when block 1 is on the ramp. Block 2 should go down.
Thanks i got it just few seconds before you reply :smile:
 
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What is the concept of incline with friction and two blocks?

The concept of incline with friction and two blocks is a physics problem that involves two blocks of different masses connected by a string and placed on an inclined plane. The force of gravity, friction, and tension in the string all play a role in determining the acceleration and motion of the blocks.

How do you calculate the net force on the system?

The net force on the system can be calculated by using Newton's Second Law of Motion, which states that the net force on an object is equal to its mass multiplied by its acceleration. In this case, the net force is the sum of the gravitational force, frictional force, and tension in the string.

What factors affect the acceleration of the blocks?

The acceleration of the blocks is affected by the angle of the incline, the masses of the blocks, the coefficient of friction between the blocks and the incline, and the tension in the string. These factors determine the net force on the system and therefore, the acceleration.

How do you account for friction in this problem?

Friction is accounted for by using the coefficient of friction, which is a measure of the resistance to motion between two surfaces. In this problem, the coefficient of friction is used to calculate the frictional force acting on the blocks and to determine the net force on the system.

Can you determine the acceleration of the blocks using only the given information?

Yes, using the laws of motion and the given information, the acceleration of the blocks can be calculated. However, in some cases, additional information may be needed, such as the coefficient of friction or the angle of the incline, to accurately determine the acceleration of the blocks.

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