Slightly downstream for the shortest possible time
Answer:
carbon dioxide (what you are blowing up the balloon with) is a heavy gas. so when you fill the Balloon with it, the balloon will not float. helium is a light gas and floats. gravity takes another. part in this
Answer:


Explanation:
Given that:
- mass of plank,

- length of plank,

From the image we can visualize the given situation.
Consider the given plank to be mass-less and having a uniformly distributed mass of 1.5 kg per meter.
<u>Now in the balanced condition:</u>

.......................(1)

...........................(2)
is the force acted by the tailgate on the plank.
<u>Substitute the value from (2) into (1):</u>
is the force acted by the wall upon the plank.
Answer:
17.97m/s
Explanation:
Density of air (ρ)air=1.23 kg/m3, and
Air speed (V) =20 m/sec, pressure gradient along the streamline, ∂p/∂x = 100N/m^3.
The equation of motion along the stream line directions:
considering the momentum balance along the streamline.
γsinθ-∂p/∂x=ρV(∂V/∂x)
Neglecting the effect of gravity , then γ=ρg=0
So, ∂p/∂x= -ρV(∂V/∂x)
∂V/∂x= - 100/(20X1.23)= -4.0650407/S
Also δV/δx=∂V/∂x
∂V/∂x=-4.0650407/S and δx=0.5 m
δV = (-4.0650407/S) *(0.5m)
δV = -2.0325203 m/S
So net air speed will be V+δV= -2.0325203+20 ≅17.96748 m/s
Approximately, V+δV=17.97m/s.