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2 years ago

1. A book resting on a shelf was found

Physics

1 answer:

Alex2 years ago

3 0

Answer:

12J

Explanation:

Right before it hits the ground, the initial potential energy and the final kinetic energy will equal each other due to conservation of energy.

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A passenger on a Ferris wheel moves in a vertical circle at a constant speed. Are the forces on her balanced?

vovikov84 [41]

C. The force is a constant change, because her position on the Ferris wheel will constantly change. I believe this is the answer, but use sources to double check. I might use different vocab. then your teachers.

6 0

3 years ago

The angular speed of the hour hand of a clock, in rad/min, is:___________

lapo4ka [179]

The angular speed is defined as:

where

$T=12*60=720min$

$\omega=\frac{2\pi}{720}$

$\omega=4.4**10^{-3} rad/min$

4 0

3 years ago

The seismic activity density of a region is the ratio of the number of earthquakes during a given time span to the land area aff

Natalija [7]

Answer:

0.0059

Explanation:

According to the question the seismic activity density is given by

$\text{Seismic activity density}=\frac{\text{Number of Earthquakes over a given time span}}{\text{The land area affected}}$

Here,

Number of Earthquakes over a given time span = 424

The land area affected = 71300 mi²

So,

$\text{Seismic activity density}=\frac{424}{71300}\\\Rightarrow \text{Seismic activity density}=0.0059$

The seismic activity density is 0.0059

8 0

3 years ago

Read 2 more answers

Match the element to the best description of its ionization energy

kompoz [17]

Ionization energy, according to chem.libretexts.org, is the quantity of energy that an isolated, gaseous atom in the ground electronic state must absorb to discharge an electron, resulting in a cation. This energy is usually expressed in kJ/mol, or the amount of energy it takes for all the atoms in a mole to lose one electron each.

4 0

3 years ago

Hey guys.. ans me

Stels [109]

The time taken by the swimmer was 1 hour.

Why?

Since the swimmer is maintaining an angle of 150° while he was swimming, there were two components of the speed (horizontal and vertical). If we want to calculate the time taken by him to cross the river, we need to calculate the vertical speed and consider that the flow's speed is compensated by his horizontal speed.

We can calculate both components of the speed using the following formula:

$HorizontalSpeed=Speed*Cos(150\°)\\\\VerticalSpeed=Speed*Sin(150\°)$

Now, calculating we have:

$HorizontalSpeed=2\frac{Km}{h} *Cos(150\°)=-\sqrt{3} \frac{Km}{h} \\\\VerticalSpeed=2\frac{Km}{h} *Sin(150\°)=1\frac{Km}{h}$

Therefore, we have that the horizontal speed is compesating the flow's speed while his vertical speed is used to cross the river which is 1 Km wide.

Hence, we have that the tame taken is:

$Time=\frac{RiverWidth}{VerticalSpeed}=\frac{1Km}{1\frac{Km}{h} } =1h$

Have a nice day!

7 0

3 years ago