When a psychologist simply records the relationship between two variables without manipulating them, it is called a correlational study.
The observed relationship does not by itself reveal which variable causes the other. This is the directionally problem. Also, the relationship may be due to a third variable controlling both of the observed variables.
Answer:
Average heat transfer =42.448w/m^2k
Nud = 13.45978
Explanation:
See attachment for step by step guide
Answer: downward velocity = 6.9×10^-4 cm/s
Explanation: Given that the
Diameter of the smoke = 0.05 mm = 0.05/1000 m = 5 × 10^-5 m
Where radius r = 2.5 × 10^-5 m
Density = 1200 kg/m^3
Area of a sphere = 4πr^2
A = 4 × π× (2.5 × 10^-5)^2
A = 7.8 × 10^-9 m^2
Volume V = 4/3πr^3
V = 4/3 × π × (2.5 × 10^-5)^3
V = 6.5 × 10^-14 m^3
Since density = mass/ volume
Make mass the subject of formula
Mass = density × volume
Mass = 1200 × 6.5 × 10^-14
Mass M = 7.9 × 10^-11 kg
Using the formula
V = sqrt( 2Mg/ pCA)
Where
g = 9.81 m/s^2
M = mass = 7.9 × 10^-11 kg
p = density = 1200 kg/m3
C = drag coefficient = 24
A = area = 7.8 × 10^-9m^2
V = terminal velocity
Substitute all the parameters into the formula
V = sqrt[( 2 × 7.9×10^-11 × 9.8)/(1200 × 24 × 7.8×10^-9)]
V = sqrt[ 1.54 × 10^-9/2.25×10-4]
V = 6.9×10^-6 m/s
V = 6.9 × 10^-4 cm/s
Answer:
The inductance of the inductor is 0.051H
Explanation:
From Ohm's law;
V = IR .................. 1
The inductor has its internal resistance referred to as the inductive reactance, X
, which is the resistance to the flow of current through the inductor.
From equation 1;
V = IX
X = 
................ 2
Given that; V = 240V, f = 50Hz, 
= 
, I = 15A, so that;
From equation 2,
X= 
= 16Ω
To determine the inductance of the inductor,
X = 2fL
L = 
= 
= 0.05091
The inductance of the inductor is 0.051H.
Answer:
Explanation:
Initial speed of the mobile = 3.2 m/s
Final speed of the mobile = 5.2 m/s
Time, t = 8 s
We need to find the acceleration of the mobile. It can be given by the change in velocity divided by time. So,
So, the acceleration of the mobile is 
.
