Question

1. a fluid flows through a pipe that narrows. describe how the speed and pressure of the fluid change in the narrow section.
2. give a real - world example where bernoullis principle is observed (other than airplane wings).
3. convert 5000 milligrams to kilograms.
4. why is speed considered as a scalar quantity and velocity as a vector quantity?
5. 350 miles/hr ne. is it scalar or vector?

Explanation:

11.

Step1: Apply continuity equation

According to the continuity equation $A_1v_1 = A_2v_2$ (where $A$ is cross - sectional area and $v$ is speed). As the pipe narrows ($A_2 v_1$).

Step2: Apply Bernoulli's principle

Bernoulli's principle for horizontal flow is $P+\frac{1}{2}
ho v^{2}=\text{constant}$. Since the speed $v$ increases in the narrow section, the pressure $P$ decreases.

When a fast - moving train passes a platform, the air between the train and the platform moves at high speed. According to Bernoulli's principle, the pressure in this region is lower than the pressure further away from the train. This can cause a person standing close to the edge of the platform to be pushed towards the train.

Step1: Know the conversion factors

We know that $1\ kg = 1000\ g$ and $1\ g=1000\ mg$. So, $1\ kg = 10^{6}\ mg$.

Step2: Perform the conversion

To convert $5000\ mg$ to $kg$, we use the formula $m_{kg}=\frac{m_{mg}}{10^{6}}$. Substituting $m_{mg} = 5000$, we get $m_{kg}=\frac{5000}{10^{6}}=0.005\ kg$.

Answer:

The speed of the fluid increases and the pressure of the fluid decreases in the narrow section.

12.