Answer:
499.73 m
Explanation:
We'll begin by calculating the change in the temperature. This can be obtained as follow:
Initial temperature (T₁) = 25 °C
Final temperature (T₂) = –20° C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = –20 – 25
ΔT = –45 °C
Finally, we shall determine the length on a cold day at –20° C. This can be obtained as follow:
Length at 25°C (L₁) = 500 m
Coefficient of linear expansion (α) = 12×10¯⁶ /°C
Change in temperature (ΔT) = –45 °C
Length at –20 °C (L₂) =?
α = L₂ – L₁ / L₁ΔT
12×10¯⁶ = L₂ – 500 / (500 × –45)
12×10¯⁶ = L₂ – 500 / –22500
Cross multiply
L₂ – 500 = 12×10¯⁶ × –22500
L₂ – 500 = –0.27
Collect like terms
L₂ = –0.27 + 500
L₂ = 499.73 m
Therefore, the length on a cold day at –20° C is 499.73 m.
A. Increasing the inertia.
As water vapour cools, it changes back into liquid form. drops come together to form 'clouds'? maybe
Answer:
lead with Z = 82 is transformed into Bismuth with Z = 73
The Po with Z = 84 becomes Pb with Z = 82
Explanation:
Beta decay occurs when a neutron emits an electron and an anti neutrino from the atomic nucleus, therefore the atomic number of the material increases by one unit.
Pb + e + ν → Bi
lead with Z = 82 is transformed into Bismuth with Z = 73
In alpha decay, a helium nucleus is emitted from the nucleus of the atom, therefore the atomic number decreases by two units.
Po +α → Pb
The Po with Z = 84 becomes Pb with Z = 82
Answer:
The ability to do something or act in a particular way, especially as a faculty or quality.
"The power of speech"