Answer:
8.333*10^-6 ohms
Explanation:
Resistivity of a material is expressed as;
p = RA/l
R is the resistance of the material
A is the cross sectional area
l is the length of the material
Given
R = 5 ohms
A = 0.5mm^2
A = 5 * 10^-7m^2
l = 30cm = 0.3m
Substitute into the formula;
p = (5 * 5 * 10^-7m^2)/0.3
p = 25 * 10^-7/0.3
p = 0.0000025/0.3
p = 8.333*10^-6
Hence its resistivity at 20 degrees Celsius is 8.333*10^-6 ohms
Answer:
It would be (a)
Explanation:
A theory is something that can be proved through rigorous and repeated experimentation, while choice (b) sounds tempting i believe it fails at the fact that it says that a theory is an "agreement", sure an agreement could be reached by while trained scientists but that does not necessarily mean that what the scientists agree upon is rigorously tested and repeatable, and so therefore cannot be assumed
That is what I think
Hope this helps :)
Answer:
NH₃
Explanation:
The compound that is covalent from the given choices is NH₃.
Covalent compounds are usually formed between two atoms with similar values of electronegativities such that the difference is very small or zero.
- This bond type involves the sharing of electrons between two atoms with similar electronegativities.
- Nitrogen and hydrogen forms stable configuration that are isoelectronic with noble gases by sharing their valence electrons.
- The 3 hydrogen electrons are enough to make nitrogen isoelectronic with neon.
- Also, the nitrogen with 3 lone pairs of electrons provides the bonding hydrogen with needed electrons to attain a structure similar to helium.
Answer:
22 revolutions
Explanation:
2 rev/s = 2*(2π rad/rev) = 12.57 rad/s
The angular acceleration when it starting
The angular acceleration when it stopping:
The angular distance it covers when starting from rest:
The angular distance it covers when coming to complete stop:
So the total angular distance it covers within 22 s is 62.8 + 75.4 = 138.23 rad or 138.23 / (2π) = 22 revolutions
Answer:
Their number should increase
Explanation:
The photoelectric effect is a phenomenon that causes the ejection of electrons from that metal as light shined onto a metal surface. Only certain frequencies of light can cause the ejection of electrons. However, if the frequency of the incident light is too low then no electrons were ejected even if the intensity of the light was very high. If the frequency of the light was higher then electrons were able to be ejected from the metal surface even if the intensity of the light was very low.
According to the accepted wave theory, light of any frequency will cause electrons to be emitted. Kinetic energy emitted by the electrons depends upon the intensity of light.
According to the accepted wave theory, number of electrons being ejected by the metal should increase
