Newtons Laws, Finding tension in the tow cable and foce

[mjm3]

Homework Statement

Just started tension problems and having some trouble figuring out how to approach the problem. Thanks for any help in advance.

Consider a rocket that is taking off and towing a large container of trash. The
rocket’s engines exert a force, F, that causes the rocket and container to accelerate at
4.50 m/s2. The rocket has a mass of 3.00 × 103 kg, and the container has a mass of
1.00 × 103 kg. Find the tension in the tow cable and the force, F.

Homework Equations

The Attempt at a Solution

 

[Enigman]

Start with free body diagram and show us what you get.

 

[mjm3]

mass a of the rocket. FN upward is the F(RA), downward we have m(ag) and also m(bg)?
mass b of container. Upward would be F(t) and FN would be F(RB)? downward m(bg).

I have the most trouble the free body diagrams.

Work. Part 1, A= F / ma+mb. F=A(ma+mb) = 1.80x10^4 N
Part 2, Ft=mb * a = 4.50x10^3 N

 

[Enigman]

Upward would be F(t) and FN would be F(RB)? downward m(bg).

What is FN?

Work. Part 1, A= F / ma+mb. F=A(ma+mb) = 1.80x10^4 N
Part 2, Ft=mb * a = 4.50x10^3 N

Seems good.

 

[mjm3]

Sorry I was meaning to write it as the Normal Force, NF better?

 

[Enigman]

Sorry I was meaning to write it as the Normal Force, NF better?

I was afraid so...there is no normal force here! Normal forces come in play when there is a body in contact with another. See: http://en.wikipedia.org/wiki/Normal_force
For normal force it is general practice to write F_n or just N.

 

[mjm3]

Thanks for the help. Just clarifying Fn made this system much easier to understand.