The laws of motion

  • Thread starter haha1234
  • Start date
  • #1
109
0

Homework Statement





Homework Equations





The Attempt at a Solution


The photo shows below is my attempted solution.
Is there any mistake so I cannot get the correct answer?
 

Attachments

  • DSC_0588[1].jpg
    DSC_0588[1].jpg
    34.4 KB · Views: 488
  • DSC_0589[1].jpg
    DSC_0589[1].jpg
    20.2 KB · Views: 287

Answers and Replies

  • #2
Andrew Mason
Science Advisor
Homework Helper
7,663
385

Homework Statement





Homework Equations





The Attempt at a Solution


The photo shows below is my attempted solution.
Is there any mistake so I cannot get the correct answer?
You have the right idea. But you have not taken into account the fact that the mug is moving during this process. So how far does the table cloth have to move?

AM
 
  • #3
109
0
I still cannot figure out the right answer:cry:
 
  • #4
1,540
135
I cannot understand your working .

Please answer the following questions:

1) What is the acceleration of the mug ?
2) What is the relative acceleration of the cloth with respect to the mug?
3) How much time does it take to pull the cloth completely out from under the mug?
 
  • #5
109
0
I cannot understand your working .

Please answer the following questions:

1) What is the acceleration of the mug ?
2) What is the relative acceleration of the cloth with respect to the mug?
3) How much time does it take to pull the cloth completely out from under the mug?
(1)I don't know if it is correct.
I found the acceleration of the mug is f=ma→0.1=0.2a→0.5ms^-1
(2)3-0.5?
(3)I don't know.:cry:
 
  • #6
1,540
135
(1)I don't know if it is correct.
I found the acceleration of the mug is f=ma→0.1=0.2a→0.5ms^-1

Correct...except the units are ms-2

(2)3-0.5?

Correct...So the relative acceleration is 2.5ms-2

(3)I don't know.:cry:
Okay...First answer this - What is the distance cloth has to move with respect to the mug so that the cloth is completely out ? (Read the question carefully ,you may get the answer in question itself )
 
Last edited:
  • #7
109
0
Correct...except the units are ms-2



Correct...So the relative acceleration is 2.5ms-2


Okay...First answer this - What is the distance cloth has to move with respect to the mug so that the cloth is completely out ? (Read the question carefully ,you may get the answer in question itself )

I don't know.
I still cannot understand and still think that the solution is as follow.- -"
0.3=0.5(3)t^2
T=0.447s

s=ut+0.5at^2
=0.5X0.5X0.447^2
=0.05m
However the correct answer is 0.06m
 
Last edited:
  • #8
1,540
135
0.3m?

Correct...

So the cloth has to move .3m with respect to the mug such that it is completely out.The relative acceleration of the cloth is 2.5ms-2 .

Now use the kinematics equation x=ut+(1/2)at2 ,where u=0 ,x=0.3m and a=2.5ms-2 .

This will give you the value of 't' i.e time it takes to pull the cloth completely out from under the mug .

What do you get ? Let the answer be in square root only.
 
  • #9
109
0
Correct...

So the cloth has to move .3m with respect to the mug such that it is completely out.The relative acceleration of the cloth is 2.5ms-2 .

Now use the kinematics equation x=ut+(1/2)at2 ,where u=0 ,x=0.3m and a=2.5ms-2 .

This will give you the value of 't' i.e time it takes to pull the cloth completely out from under the mug .

What do you get ? Let the answer be in square root only.
Thank you!
I can get the correct answer now.:rofl:
 
  • #10
1,540
135
Thank you!
I can get the correct answer now.:rofl:

:thumbs:
 

Related Threads on The laws of motion

  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
884
  • Last Post
Replies
1
Views
683
  • Last Post
Replies
9
Views
2K
  • Last Post
Replies
7
Views
2K
  • Last Post
Replies
16
Views
2K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
1
Views
3K
Replies
2
Views
4K
Top