Mass of the rocket doesnt stay constant

[spri4]

My physics class is ending the year with the study of rockets. He said it will be one of the most difficult studys of physics because the mass of the rocket doesn't stay constant. What do you think? Any hints/tips you would like to share? Thank you.

 

[AzonicZeniths]

Hints? Tips? ummmmmmmm... PAY ATTENTION ;)

But seriously it shouldn't be that hard, you just have to factor in how much weight in fuel the rockets are averaging over 3 stages in flight (take off, level flight, descent) as each will be different. But, then we should also remember relativity, which states that mass increases as speed increases, and that size (in the direction of thrust) also becomes smaller.

 

[kamerling]

Hints? Tips? ummmmmmmm... PAY ATTENTION ;)

But seriously it shouldn't be that hard, you just have to factor in how much weight in fuel the rockets are averaging over 3 stages in flight (take off, level flight, descent) as each will be different. But, then we should also remember relativity, which states that mass increases as speed increases, and that size (in the direction of thrust) also becomes smaller.

I don't think relativity will be in this class

 

[pam]

Use conservation of momentum.