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3 years ago

8

A 25 kg rock resting on the bottom of a lake must be moved from the paths of boats. The rock has a density of 2350 kg/m^3. What

force is needed to lift the rock while under water?

1 answer:

algol133 years ago

7 0

Answer:

The force needed is the weight of the rock minus the buoyant force.

Explanation:

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Which element could provide one atom to make an ionic bond with nitrogen?

aev [14]

Answer:

boron

aluminum

gallium

indium

thallium

Explanation:

Any of these could work. Nitrogen has 5 valence electrons so you just needed to pick an element that has 3 valence electrons that nitrogen could borrow. This periodic table shows valence electron counts:

8 0

3 years ago

A newly discovered particle, the SPARTYON, has a mass 945 times that of an electron. If a SPARTYON at rest absorbs an anti-SPART

Gennadij [26K]

Answer:

$\nu =1166\times 10^{20}Hz$

Explanation:

We have given the rest mass of SPARTYON = 945 times of mass of electron

We know that mass of electron $=9.11\times 10^{-31}kg$

So mass of SPARTYON $=945\times 9.11\times 10^{-31}=8608.95\times 10^{-31}kg$

Speed of light $c=3\times 10^8m/sec$

According to Einstein equation energy is given by

$E=mc^2=8608.95\times 10^{-31}\times (3\times 10^{8})^2=77480.55\times 10^{-15}j$

Now according to planks's rule

Energy is given by

$E=h\nu$ , here h is plank's constant $h=6.6\times 10^{-34}$

So $77480.55\times 10^{-15}=6.6\times 10^{-34}\nu$

$\nu =1166\times 10^{20}Hz$

3 0

3 years ago

Which is true about Pluto

andrew-mc [135]

Answer:

D.)it orbits near the Kepler belt

Explanation:

The Kuiper belt is an area similar to the asteroide belt extending from the orbit of Neptune to about 50 AU from the Sun. It mainly consists of icy asteroids and dwarf planets, which are rocky objects big enough to be defined as planet but that do not have enough gravity to clear their orbit from other obejcts.

Pluto was discovered in 1930 - initially it was classified as a planet, although it is much smaller than the other 8 planets of the Solar System. However, it has been recently de-classified to dwarf planet because its gravity is not enough to clear its orbit from other objects (asteroids). Pluto is located inside the Kuiper belt, so option D is correct. Other dwarf planets in the Kuiper belt are for instance Haumea and Makemake.

8 0

3 years ago

Read 2 more answers

Two horses on opposite sides of a narrow stream are pulling a barge up the stream. Each hors pulls with a force of 720N. The rop

anygoal [31]

For the answer to the question above, each horse's force forms a right angle triangle with the barge and subtends an angle of 60/2 = 30°. The resultant in the direction of the barge's motion is:
Fx = Fcos(∅)
We can multiply this by 2 to find the resultant of both horses.
Fx = 2Fcos(∅)
Fx = 2 x 720cos(30)
Fx = 1247 N

3 0

3 years ago

Can someone please answer this pleaseeeee!!!!!!!!

WITCHER [35]

Answer:

it will move in the opposite direction because of Newton's 3rd law

3 0

4 years ago