Answer:
Explanation:what’s the answer ?
Answer:
Double blind experiment
Explanation:
It is an experimental method , which helps to avoid any impartiality and any error due to biasing .
The experiment give rise to very accurate results , which is very important for any experiment .
Hence , the new director Margaret , need to design a set of double - blind experiments.
Answer:
E = 4.83 N/ C
Explanation:
If we have a uniform charge sphere we can use the following formulas to calculate the Electric field due to the charge of the sphere:
: Formula (1) To calculate the electric field in the region outside the sphere r ≥ a
Where:
K: coulomb constant (N*m²/C²)
a: sphere radius (m)
Q: Total sphere charge (C)
r : Distance from the center of the sphere to the region where the electric field is calculated (m)
Equivalences
1nC=10⁻⁹C
1cm= 10⁻²m
Data
k= 9*10⁹ N*m²/C²
Q=4nC=4 *10⁻⁹C
D = 26 cm = 26*10⁻²m = 0.26m
a = D/2 = 0.13m
r= R+a = 2.6 m+ 0.13m = 2.73m
Problem development
Magnitude of the electric field at r = 2.73m from the center of the sphere
r>a , We apply the Formula (1) :


E= 4.83 N/ C
This is happened because "the air" above "moves faster" and "the pressure" is "lower"
.
Option: 1
<u>Explanation</u>:
Air movement take place from the region where air pressure is more than the region where the pressure is low. When we "blow" air above the "paper strip" paper rises because "low pressure" is created above the strip as high speed winds always travel with reduced air pressure. Hence due to higher air pressure below the strip, it is pushed upwards. This difference in pressure results into fast air moves. This happen because "speed" of the wind depends on "the difference between the pressures" of the air in the two regions.