Solving Tension: Helicopter Lifts 2 Crates

[lalahelp]

Homework Statement

A helicopter is lifting two crates simultaneously. One crate with a mass of 120 kg is attached to the helicopter by cable A. The second crate with a mass of 76 kg is hanging below the first crate and attached to the first crate by cable B. As the helicopter accelerates upward at a rate of 1.2 m/s2, what is the tension in each of the two cables?


I don't understand how to solve this at all can you please help ??

 

[Doc Al]

Draw a free body diagram for each crate. What forces act on each? Then apply Newton's 2nd law.

 

[lalahelp]

-mg+Tb=ma
76(1.2+9.8)= 836 N For Crate B

Ta=ma+mg+836
=120(1.2+9.8)+836
=2156 N

Are these answers correct?

 

[Doc Al]

-mg+Tb=ma
76(1.2+9.8)= 836 N For Crate B

Ta=ma+mg+836
=120(1.2+9.8)+836
=2156 N

Are these answers correct?

Yes!

 

[lalahelp]

Thank you!