Answer:
Hipparchus was an ancient Greek who classified stars based on the brightness in 129 B.C. He grouped the brightest stars and ranked them 1 (first magnitude) and dimmest stars as 6 (sixth magnitude). Thus, the smaller numbers indicated brighter stars. Now, the scale extends in negative axis as well. More the negative number, brighter is the star. For example, Sun has magnitude -26.74.
This the apparent magnitude which means the classification is based on the brightness of the star as it appears from the Earth.
The formula is
F_grav = G * m1 * m2 / r^2
G m1 and m2 are going to stay the same once chosen no matter what the distance is. The only thing that will change is the distance.
As the distance increases, the Gravitational Force will decrease. It will decrease by quite a bit.
As the distance decreases, the gravitational force will Increase.
The relationship is inverse. The moon travelling around the earth is one example. The earth travelling around the sun is another.
Answer:
Thickness of Styrofoam insulation is 0.02741 m.
Explanation:
Given that,
Height = 0.25 m
Depth = 0.5 m
Power = 400 W
Temperature = 33°C
We need to calculate the area of Styrofoam
Using formula of area
Put the value into the formula
Inner surface temperature of freezer
Outer surface temperature of freezer
We need to calculate the thickness of Styrofoam insulation
Using Fourier law,
Put the value into the formula
Hence, Thickness of Styrofoam insulation is 0.02741 m.
While he is lifting the dumbell as the definition of work done = moving a mass through a distance = F x d
