Answer:

Explanation:
When the screw is turned by two turns then change in the length of the wire is given as




now we know by the formula of Young's modulus

so we have



Answer:
<em>I think the answer is C</em>
<em />
Explanation:
Its heavy but not too heavy
Density is the characteristic property of a substance. It is the measure of mass of the substance
divided by its volume (density= mass/volume). Manipulate the given formula to
come up with the formula for the volume. Therefore, volume is equals to mass of
a substance divided by its density (Vol= mass/density). Given 12.6 g/ml as density
and 7.65 g mass, volume is equals to 0.60714 ml, since 1 ml = 1cm^3, volume is
equals to 0.60714 cm^3 then extract the cube root of the volume to get the
length of the cube in cm which is equal to 0.84677 cm.
First, we have to calculate the normal forces on different surfaces.The normal force on the 4.00 kg, N1 = (4)(9.8) = 39.2 N. The normal force on the 10.0 kg, N2 = (14)(9.8) = 137.2 N. Looking at the 10.0 kg block, the static forces that counteract the pulling force equals the sum of the friction from the two surfaces. Fc = N1 * 0.80 + N2 * 0.80 = 141.12 N. Since the counter force is less than the pulling force, the blocks start to move and hence, kinetic frictions are considered.
Therefore, f1 = uk * N1 = (0.60)(39.2) = 23.52 N.
<h3><u>Answer</u>;</h3>
= 22°
<h3><u>Explanation</u>;</h3>
- According to Snell's law, the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant. The constant value is called the refractive index of the second medium with respect to the first.
- Therefore; Sin i/Sin r = η
In this case; Angle of incidence = 90° -60° =30°, angle of refraction =? and η = 1.33
Thus;
Sin 30 / Sin r = 1.33
Sin r = Sin 30°/1.33
= 0.3759
r = Sin^-1 0.3759
= 22.08
<u>≈ 22°</u>