42.6 is the answer I believe because you would do 2,560 divided by 60 if I'm correct.
F=K*X,
F=M*a
M*a=K*X
2.5*9.81=K*0.0276
24.525=K*0.0276
24.525/0.0276=K
K= 888.6 N/m ---- force constant
assuming 2.5 refers to the new extension, just divide F/ 0.025
to get
981N/m
You have traveled 390 km. In order to find your answer all you have to do is multiply your speed which is 130 km/h by 3 hrs. That's my friend is how you get your answer! Have a great day!
The third option seems correct. Using any bag more than once will help in decreasing the carbon foot print.
This isds beause, if you use paper bag once only, then paper bag is being utilised and more and more paper is being used. So the best way is to use the bag more than once, whichever bag u are using.