All categories

3 years ago

When the mass of the sun is larger, Earth moves around the sun at a faster or slower pace.

1 answer:

4 0

-- The mass of the sun never increases.

-- It does decrease, but not nearly enough to have any noticeable
effect on the orbital motion of the Earth, or any other planet.

-- When Earth is closer to the sun, it moves faster in its orbit.

-- When Earth is farther from the sun, it moves slower in its orbit.

-- The result is that the line from the sun to the Earth always covers
the same amount of area in the same length of time.

-- Johannes Kepler noticed this, and it's his Second Law of planetary motion.

-- Newton showed that if his equations for gravity and motion are correct,
then planets MUST behave this way.

You might be interested in

Starting from Newton’s law of universal gravitation, show how to find the speed of the moon in its orbit from the earth-moon dis

WARRIOR [948]

Answer: 1010.92 m/s

Explanation:

According to Newton's law of universal gravitation:

$F=G\frac{Mm}{r^{2}}$ (1)

Where:

$F$ is the gravitational force between Earth and Moon

$G=6.674(10)^{-11}\frac{m^{3}}{kgs^{2}}$ is the Gravitational Constant

$M=5.972(10)^{24} kg$ is the mass of the Earth

$m=7.349(10)^{22} kg$ is the mass of the Moon

$r=3.9(10)^{8} m$ is the distance between the Earth and Moon

Asuming the orbit of the Moon around the Earth is a circular orbit, the Earth exerts a centripetal force on the moon, which is equal to $F$ :

$F=m.a_{C}$ (2)

Where $a_{C}$ is the centripetal acceleration given by:

$a_{C}=\frac{V^{2}}{r}$ (3)

Being $V$ the orbital velocity of the moon

Making (1)=(2):

$m.a_{C}=G\frac{Mm}{r^{2}}$ (4)

Simplifying:

$a_{C}=G\frac{M}{r^{2}}$ (5)

Making (5)=(3):

$\frac{V^{2}}{r}=G\frac{M}{r^{2}}$ (6)

Finding $V$ :

$V=\sqrt{\frac{GM}{r}}$ (7)

$V=\sqrt{\frac{(6.674(10)^{-11}\frac{m^{3}}{kgs^{2}})(5.972(10)^{24} kg)}{3.9(10)^{8} m}}$ (8)

Finally:

$V=1010.92 m/s$

5 0

3 years ago

A box weighs 100N and its base area of 2 m2. What pressure does it exert on the ground?

kotegsom [21]

Answer:

P = F/S = 100/2 =50 (N/m2)

5 0

3 years ago

Help meee please fill in the blanks !!

Ratling [72]

The atomic number is the simply the number of protons in the atom. So in the first row with atomic number 2, the number of protons is 2.

If the atom has no charge, which I think you can assume for all of these, the number of electrons is equal to the number of protons. So the number of electrons is also 2.

The number of neutrons (which are the particles with no charge in the nucleus) is simply the mass number minus the atomic number i.e. 4 - 2 = 2.

The isotopic symbol is the symbol which is found on the periodic table of elements. There are 2 numbers associated which each element on the table. The larger is the mass number and the smaller is the atomic number. The atomic number or number of protons is what identifies the element. Looking at the periodic table ( https://sciencenotes.org/wp-content/uploads/2015/01/PeriodicTableOfTheElementsBW.pdf or https://simple.wikipedia.org/wiki/Periodic_table_(big) ), it can be seen that the element on the first row above with an atomic number of 2 is Helium with a symbol He. The number that is included with the name is simply the mass number which is 4 in this case, which tells us that this type of helium has 2 neutrons.

Another type (or isotope) of helium is Helium-3 which has one neutron.

Try the next row and post back if you have trouble with it

3 0

3 years ago

Blake and Sandra are having a rummage sale. Blake drags 3 boxes a distance of 10 meters each. He exerts a force of 20 newtons on

vampirchik [111]

For Blake:

3 boxes at a distance of 10 meters each, each box weighs 20 N

Work done by Blake = 3 * 10m * 20N
= 600 J
Power = 600 J/ 2 min
= 300 J/min

For Sandra:

4 boxes, 15 N each at a distance of 12 meters each.

Work done by Sandra = 4 * 15 N *12m
= 720 J
Power = 720 J/ 4 min
= 180 J/min

Blake does less work than Sandra.
Blake's power is more than Sandra's.

5 0

3 years ago

Read 2 more answers

how much energy must be transferred to a normal incandescent bulb (efficiency 0.05) for it to transfer 9J of energy by light?

oksian1 [2.3K]

Answer:

Revise energy transfers and use sankey diagrams to calculate the efficiency of these conversions with BBC ... Efficiency is a measure of how much useful energy is converted. Part of ... This is the Sankey diagram for a typical filament lamp: 100 joules of electrical energy is converted to 10 joules of light energy and 90 joules.

Explanation:

3 0

3 years ago