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.
There are some missing data in the text of the problem. I've found them online:
a) coefficient of friction dry steel piston - steel cilinder: 0.3
b) coefficient of friction with oil in between the surfaces: 0.03
Solution:
a) The force F applied by the person (300 N) must be at least equal to the frictional force, given by:

where

is the coefficient of friction, while N is the normal force. So we have:

since we know that F=300 N and

, we can find N, the magnitude of the normal force:

b) The problem is identical to that of the first part; however, this time the coefficienct of friction is

due to the presence of the oil. Therefore, we have:
Just find the density of every metal and select the one with a density of 2.71 g/cm³ . This is:
Metal 1
ρ = m/V
ρ = 22.1 g / 3 cm³
ρ = 7.367 g / cm³
Metal 2
ρ = m/V
ρ = 42 g / 4 cm³
ρ = 10.5 g / cm³
Metal 3
ρ = m/V
ρ = 9.32 g / 5 cm³
ρ = 1.864 g / cm³
Metal 4
ρ = m/V
ρ = 8.13 g / 3 cm³
ρ = 2.71 g / cm³
<h2>R / Metal 4 was selected.</h2>
Where they slide over each other.
Transform boundaries are formed or occur when two plates slide past each other in a sideways motion. They do not tear or crunch into each other (but the rock in between them may be ground up) and therefore none of the spectacular features are seen such as occur in divergent and convergent boundaries.
In a transform boundary, neither plate is added to at the boundary nor destroyed. They are marked in some places by features like stream beds that have been split in half and the two halves moved in opposite directions.
Answer:
Explanation:
Normal length of spring = 28.3 cm
stretched length of spring = 38.2 cm
length of extension = 38.2 - 28.3 = 9.9 cm
= 9.9 x 10⁻² m
force applied to stretch = .55 x 9.8 ( mg )
= 5.39 N
Force constant = force applied / extension
= 5.39 / 9.9 x 10⁻²
= .5444 x 10² N /m
= 54.44 N/m