**Answer:**

**P=1113.35 psi**

**Explanation:**

For tank 1

V₁= 6.25 L

P₁=1759 psi

For tank 2

V₂=6.25 L

P₂=467.7 psi

Lets take final pressure is P

The final volume V= 6.25 + 6.25 L = 12.5 L

P V = V₂P₂+V₁P₁

Now by putting the values

P V = V₂P₂+V₁P₁

P x 12.5 = 6.25 x 467.7+6.25 x 1759

**P=1113.35 psi**

So the final volume of the system will be 1113.35 psi.

I would think that you would have to do 42/2=21Hz, but I'm not sure...

**Answer:**

** 76969.29 W**

**Explanation:**

Applying,

P = F×v............. Equation 1

Where P = Power, F = force, v = velocity

But,

F = ma.......... Equation 2

Where m = mass, a = acceleration

Also,

a = (v-u)/t......... Equation 3

Given: u = 0 m/s ( from rest), v = 12.87 m/s, t = 3.47 s

Substitute these values into equation 3

a = (12.87-0)/3.47

a = 3.71 m/s²

Also Given: m = 1612 kg

Substitute into equation 2

F = 1612(3.71)

F = 5980.52 N.

Finally,

Substitute into equation 1

P = 5980.52×12.87

P = 76969.29 W

**Answer:**

0.76 mg/s

**Explanation:**

0.46 kg/week × (1 week / 7 days) × (1 day / 24 hrs) × (1 hr / 3600 s) × (1000 g/kg) × (1000 mg/g) = 0.76 mg/s