Answer:
2500 J
Explanation:
We can solve the problem by using the first law of thermodynamics:

where
Uf is the final internal energy of the system
Ui is the initial internal energy
Q is the heat added to the system
W is the work done by the system
In this problem, we have:
Q = +1000 J (heat that enters the system)
W = +500 J (work done by the system)
Ui = 2000 J (initial internal energy)
Using these numbers, we can re-arrange the equation to calculate the final internal energy:

I’m assuming D because it’s the most reasonable
first object gors highest
second object goes lowest.
Cerebrospinal fluid or Hydrocephalus
Answer:
Acceleration, 
Explanation:
Initial velocity of a particle in vector form, u = (-5i - 2j) m/s
Final velocity of particle in vector form, v = (-6i + 7j) m/s
Time taken, t = 8 seconds
We need to find the magnitude of acceleration vector. The changing of velocity w.r.t time is called acceleration of a particle. It is given by :

or

Hence, the value of acceleration vector is solved.