For no.4 is what seismologists use two main devices to measure an earthquake: a seismograph and aseismoscope. The seismographis an instrument that measures seismic waves caused by an earthquake. The seismographhas three main devices, theRichter Magnitude Scale, theModified Mercalli Intensity Scale, and the Moment-Magnitude Scale.
Answer:
(1) 1×10⁻⁴
Explanation:
From the question,
α = (ΔL/L)/(ΔT)............. Equation 1
Where α = linear expansivity of the metal plate, ΔL/L = Fractional change in Length, ΔT = Rise in temperature.
Given: ΔL/L = 1×10⁻⁴, ΔT = 10°C
Substitute these values into equation 1
α = 1×10⁻⁴/10
α = 1×10⁻⁵ °C⁻¹ .
β = (ΔA/A)/ΔT................... Equation 2
Where β = Coefficient of Area expansivity, ΔA/A = Fractional change in area.
make ΔA/A the subject of the equation
ΔA/A = β×ΔT.......................... Equation 3
But,
β = 2α.......................... Equation 4
Substitute equation 4 into equation 3
ΔA/A = 2α×ΔT................ Equation 5
Given: ΔT = 5°C, α = 1×10⁻⁵ °C⁻¹
Substitute into equation 5
ΔA/A = ( 2)×(1×10⁻⁵)×(5)
ΔA/A = 10×10⁻⁵
ΔA/A = 1×10⁻⁴
Hence the right option is (1) 1×10⁻⁴
Answer:
Explanation:
The sum of the kinetic and electric potential energies of the proton when initially released must be equal to their sum at infinity, so we have:
Which, since 
because initially the proton is at rest, is:
where 
is Coulomb's constant, 
the charge of the proton, 
the charge of the gold nucleus, since it has 79 protons, 
the initial separation between them, 
the mass of the proton and v its final velocity. 
is very far away, so the final electric potential will be 0J, and we have:
