Answer:
metal> metalloids >nonmetals (Electrical conductivity)
Explanation:
Electrical conductivity of objects can be compared by the bonding energy of electrons in them.
Metals have less bonding energy of electrons, so even at room temperature their are significant number of free electrons to carry electrical current.
Nonmetals have a very high bonding energy of electrons, so at room temperature negligible number of free electrons are present so electrical conductivity is very low.
Metalloids have both metallic and non metallic features. The electron bonding energy falls in between that of metals and nonmetals. So electrical conductivity also lies in between metals and nonmetals.
Answer:
Explanation:
v = 50 km / h
= 13.89 m /s
When a vehicle runs on a circular path , it is static friction which prevents it from getting overturned .
static friction = μs mg
centripetal force = m v² / R
m v² / R = μs mg
R = v² / μs x g
= 13.89² / .7 x 9.8
= 28.12 m .
Answer:
Explanation:
ΔE = Δm × c^2
where,
ΔE = change in energy released with respect to change in mass
= 1.554 × 10^3 kJ
= 1.554 × 10^6 J
Δm = change in mass
c = the speed of light.
= 3 × 10^8 m/s
Equation of the reaction:
2H2 + O2 --> 2H2O
Mass change in this process, Δm = 1.554 × 10^6/(3 × 10^8)^2
= 1.727 × 10^-11 kg
The change in mass calculated from Einstein equation is small that its effect on formation of product will be negligible. Hence, law of conservation of mass holds correct for chemical reactions.
Answer: option c: It orbits beyond the Earth's atmosphere to avoid scattering of light.
Explanation:
Hubble space telescope orbits Earth and sends images of distant objects. The images formed by Hubble are better than the optical telescopes used on land. This is because the Hubble telescope is a space telescope. Light from the distant objects when reaches the land telescopes transmits through atmosphere, where scattering occurs. Some the light rays bounce back. This is avoided by the space telescope Hubble.
Answer:
811.54 W
Explanation:
Solution
Begin with the equation of the time-averaged power of a sinusoidal wave on a string:
P = 
μ.T².ω².v
The amplitude is given, so we need to calculate the linear mass density of the rope, the angular frequency of the wave on the rope, and the frequency of the wave on the string.
We need to calculate the linear density to find the wave speed:
μ = 
= 0.123Kg/3.54m
The wave speed can be found using the linear mass density and the tension of the string:
v= 22.0 ms⁻¹
v = f/λ = 22.0/6.0×10⁻⁴
= 36666.67 s⁻¹
The angular frequency can be found from the frequency:
ω= 2πf=2π(36666.67s−1) = 2.30 ×10⁻⁵s⁻¹
Calculate the time-averaged power:
P =
μΤ²×ω²×ν
= ×( 0.03475kg/m)×(0.0002)²×(2.30×10⁵)² × 22.0
= 811.54 W
