Answer:
Use of telemetry and radar astronomy
Explanation:
An astronomical Unit (AU) is a unit of measuring distances in outer space, which is based on the approximate distance between the earth and the Sun.
After several years of trying to approximate the distance between the Sun and the Earth using several methods based on geometry and some other calculations, advancements in technology made available the presence of special motoring equipment, which can be placed in outer space to remotely monitor and measure the position of the sun.
The use of direct radar measurements to the sun (radar astronomy) have also made the determination of the AU more accurate.
A standard radar pulse of known speed is sent to the Sun, and the time with which it takes to return is measured, once this is recorded, the distance between the Earth and the Sun can be calculated using
distance = speed X time.
However, most of these means have to be corrected for parallax errors
Answer:
451.13 J/kg.°C
Explanation:
Applying,
Q = cm(t₂-t₁)............... Equation 1
Where Q = Heat, c = specific heat capacity of iron, m = mass of iron, t₂= Final temperature, t₁ = initial temperature.
Make c the subject of the equation
c = Q/m(t₂-t₁).............. Equation 2
From the question,
Given: Q = 1500 J, m = 133 g = 0.113 kg, t₁ = 20 °C, t₂ = 45 °C
Substitute these values into equation 2
c = 1500/[0.133(45-20)]
c = 1500/(0.133×25)
c = 1500/3.325
c = 451.13 J/kg.°C
Answer:
a)
m/s
b)
Angular frequency =
Explanation:
As we know
q is the charge on the electron = C
B is the magnetic field in Tesla = T
r is the radius of the circle = m
mass of the electrons = Kg
a)
Substituting the given values in above equation, we get -
m/s
b)
Angular frequency =
Answer:
Approximately , assuming that the gravitational field strength is .
Explanation:
Let denote the required angular velocity of this Ferris wheel. Let denote the mass of a particular passenger on this Ferris wheel.
At the topmost point of the Ferris wheel, there would be at most two forces acting on this passenger:
- Weight of the passenger (downwards), , and possibly
- Normal force that the Ferris wheel exerts on this passenger (upwards.)
This passenger would feel "weightless" if the normal force on them is - that is, .
The net force on this passenger is . Hence, when , the net force on this passenger would be equal to .
Passengers on this Ferris wheel are in a centripetal motion of angular velocity around a circle of radius . Thus, the centripetal acceleration of these passengers would be . The net force on a passenger of mass would be .
Notice that . Solve this equation for , the angular speed of this Ferris wheel. Since and :
.
.
The question is asking for the angular velocity of this Ferris wheel in the unit , where . Apply unit conversion:
.