Can you please help me with this physics question

Answer:
See the answers below
Explanation:
We can solve both problems using vector sum.
a)
Let's assume the forces that help the diver dive as positive downward, and the forces that oppose upward, as negative
[tex]F_{resultant}=100+30-85+900\\F_{resultant}=845[N][/tex]
The drag force is horizontal d this way in the horizontal direction we will only have the drag force that produces the water stream.
[tex]F_{drag}=50[N][/tex]
b)
Let's assume the forces that propel the rocket upwards as positive and forces like the weight of the rocket and other elements as negative forces.
[tex]F_{resultant}=960+7080-7700\\F_{resultant}=340 [kN][/tex]