Answer:Orient your line of sight directly above the measurement markings.
Explanation: parallax error is a type of systematic error that occurs when an observer views a measurement marking at a wrong angle. This causes a noticeable disparity in results obtained. Therefore the best way to prevent this error is to view and record the data from the correct angle. This can be obtained by:
-Place the measurement device on its edge so it is level with the object being measured.
-Seek out the finest possible edge of the measurement device, or use a device with finer edges.
In conclusion, ask other observers to also take the reading and get an average of their results. It can help cancel out parallax error results.
Answer:
3.85*10^8m
Explanation:
We know that
Speed v = distance/time t
So distance = v x t
So = 3*10^8 x 2.56s
= distatance = 7.7*10^8m
However this is double the distance from the earth to the moon, so to get distance from earth to the moon we divide by 2
7.7*10^8/2= 3.85*10^8m
Answer
given,
flow rate = p = 660 kg/m³
outer radius = 2.8 cm
P₁ - P₂ = 1.20 k Pa
inlet radius = 1.40 cm
using continuity equation
A₁ v₁ = A₂ v₂
π r₁² v₁ = π r₁² v₂



Applying Bernoulli's equation





v₂ = 1.97 m/s
b) fluid flow rate
Q = A₂ V₂
Q = π (0.014)² x 1.97
Q = 1.21 x 10⁻³ m³/s