• Support PF! Buy your school textbooks, materials and every day products Here!

Newtons third law problem

  • #1

Homework Statement



Two boxes are in contact with each other, both different mases, and are both being pulled by an external force, F.

M1M2--------->F

I can calculate the acceleration of the system but the Question asks to calculate the force between the mases, ie newtons third law. If you can either draw me the FBD or solve the question that would be helpful. M1 = 1.2 X 10^-3 kg, m2 = 0.147kg, F = 0.6 N

Homework Equations



F = ma

The Attempt at a Solution



a system = net force/total mases in system

= 0.6 N (1.2 X 10^-3 Kg + 0.147 kg)

= 4.048 m/s^2

FBD:
Fn
^
Fc <----m1---->F

Fg (Where Fc is the force between the two objects)


Fn

^
m2----->F
----->Fc
Fg
 

Answers and Replies

  • #2
Delphi51
Homework Helper
3,407
10
The F appears to act on m2, so on m1 you will only have Fc to the right.
On m2, you will have Fc to the left, F to the right. This gives you two F=ma equations which you can solve to find the two unknowns Fc and a.

Or, since you already have the acceleration, you could just calculate the force needed to make m1 accelerate that much. That is just using the known acceleration in the m1 equation.
 
  • #4
Delphi51
Homework Helper
3,407
10
Most welcome!
 

Related Threads on Newtons third law problem

  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
10
Views
7K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
4
Views
10K
  • Last Post
Replies
5
Views
3K
  • Last Post
Replies
4
Views
790
  • Last Post
Replies
1
Views
1K
Top