This gots to be the answer, average, seawater in the world's oceans has a salinity of approximately 3.5%, or 35 parts per thousand.
Answer:
306500 N/C
Explanation:
The magnitude of an electric field around a single charge is calculated with this equation:

With ε0 = 8.85*10^-12 C^2/(N*m^2)
Then:

E(0.89) = 306500 N/C
Answer:
Well a s the temperature increases, at a certain point called the Curie temperature, a magnet will lose its strength completely. So once the metal cools, its ability to attract magnets returns, though its permanent magnetism becomes weak. In general heat is the factor that has the most effect on permanent magnets.Explanation:
Answer:
Coefficient of friction between the book and floor is 0.582.
Explanation:
Using the velocity formula;
v^2 = 2as
a = v^2/(2s)
a = 1.6^2/(2*0.9)
a = 2.56/1.8
a = 1.42 m/s^2
the force necessary to give the book the acceleration is
F = ma = 3.5*1.42 (m is mass of the book i.e. 3.5 kg)
F = 4.98 N
The difference in the force is the friction force, which is
Ff = 25 - 4.98 = 20 N
Ff = mgμ
where μ is coefficient of friction and g is acceleration due to gravity that is 9.8 m/s^2
μ = Ff/mg
μ = 20/(3.5*9.81)
μ = 0.582
Coefficient of friction between the book and floor is 0.582.
Given that the mass is m = 0.2 kg and the displacement is x = 3 cm = 0.03 m
We have to find the spring constant and potential energy.
The spring constant can be calculated by the formula

Here, k is the spring constant.
g = 9.8 m/s^2 is the acceleration due to gravity.
Substituting the values, the spring constant will be

The potential energy can be calculated as