G=(6.67x10^-11 Nm^2/Kg^2)(6.4x10^23 Kg)<br> /3396km^2

Which statement correctly describes why a compound is a pure substance?

ad-work [718]

Explanation:

A compound is a pure substance composed of two or more different atoms chemically bonded to one another. A compound can be destroyed by chemical means. It might be broken down into simpler compounds, into its elements or a combination of the two.

6 0

3 years ago

A bullet of 10g strikes a sand bag at a speed of 100 m/s and gets embedded after travelling

Tasya [4]

Answer:

Solving for time :

(There are 4 formulas from linear motion. These formulas are very helpful as it allows us to prevent complicated calculations. Choose among the four that has : 1. The most constants known

2. The unknown constant that we want to solve)

s = (1/2)(u+v)t <--- one of the formulas

from linear motion

s (distance) = 0.05m

u (initial velocity) = 100m/s

v (final velocity) = 0 m/s (it stops)

t (time taken for change in velocity) = to be found

0.05 = (1/2)(100+0)t

t = 0.001 seconds

Solving for the resistant force :

Since the bullet hits the bag with an impulsive force and stops, the force that stops the bullet is the resistant force.

When the bullet stops :

F net = 0

F r = F imp

F r = (mu -mv)/t

F r = (0.01x100-0.01x0)/0.001

F r = 1/0.001

F r = 1000N

4 0

3 years ago

I NEED HELP PLEASE, THANKS! :)

Yuliya22 [10]

Answer:

Radio waves have a wavelength between $10^{-9}m$ and $10^{-12}m$

While,

X rays have a wavelength between 1m and 10km.

=> It is one of the condition of diffraction that the obstacle (coming in the way) must be comparable with the size of the wavelength.

=> This shows, that radio waves have a wavelength which is comparable with the size of buildings and can really easily diffract through it

=> While, X-rays are big enough to diffract through the wall.

So, if an X-ray technician stands behind a wall during the use of her machine, she will remain safe.

6 0

3 years ago

A car of 900 kg mass is moving at the velocity of 60 km/hr. It is brought into rest at 50 meter distance by applying a brake. No

kozerog [31]

Answer: $-2502N$

Explanation:

$(V_2)^2=(V_1)^2+2ad$

where;

$V_2$ = final velocity = 0

$V_1$ = initial velocity = 60 km/h = 16.67 m/s

$a$ = acceleration

$d$ = distance

First all of, because acceleration is given in m/s and not km/h, you need to convert 60km/h to m/s. Our conversion factors here are 1km = 1000m and 1h = 3600s

$60km/h(\frac{1000m}{1km} )(\frac{1h}{3600s} )=16.67m/s$

Solve for a;

$(V_2)^2=(V_1)^2+2ad$

Begin by subtracting $(V_1)^2$

$(V_2)^2-(V_1)^2=2ad$

Divide by 2d

$\frac{(V_2)^2-(V_1)^2}{2d} =a$

Now plug in your values:

$a=\frac{(0)^2-(16.67 m/s)^2}{2(50m)}$

$a=\frac{0-277.89m^2/s^2}{100m}$

$a=-2.78m/s$

If you're wondering why I calculated acceleration first is because in order to find force, we need 2 things: mass and acceleration.

$F=ma$

m = mass = 900kg

a = acceleration = -2.78m/s

$F=(900kg)(-2.78m/s)\\F=-2502N$

It's negative because the force has to be applied in the opposite direction that the car is moving.

8 0

3 years ago

The automobile beltway around many cities is approximately circular. Suppose that you start driving at point A on the east side

lord [1]

speed is the magnitude of velocity which is given as 90 km/hr and it does not change. only the direction change , the direction at any time is given by the tangent to the circle at that time and location.

from the diagram , at north side, the velocity is directed in west direction

5 0

3 years ago

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G=(6.67x10^-11 Nm^2/Kg^2)(6.4x10^23 Kg) /3396km^2