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4 years ago

Which is not an element? Water , Arsenic, sodium, Aluminum

Physics

2 answers:

Lilit [14]4 years ago

6 0

Answer: Water

Explanation: water is a molecule and composed of Hydrogen and Oxygen atoms.

MrRa [10]4 years ago

3 0

Answer:

water

Explanation:

water is not an element, it is a molecule

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A converging lens can produce both real and virtual images depending on the position of the object. Explain when converging lens

inessss [21]

Answer: C

Explanation:

5 0

3 years ago

Read 2 more answers

A centrifuge is a device used to separate materials by their masses. A sample in a centrifuge is rotated at high speeds along a

german

Answer:

F = 1.047 10⁻² N

Explanation:

Let's use kinematics to find the angular acceleration

w = w₀ + α t

as for rest w₀ = 0

w = α t

α = w / t

let's reduce the magnitudes to the SI system

w = 1000 rev / min (2π rad/ 1 rev) (1 min/ 60s) = 104.72 rad / s

m = 1.00 g (1 kg / 1000 g) = 1,000 10⁻³ kg

r = 10.0 cm (1 m / 100 cm) = 0.100 m

let's calculate

α = 104.72 / 1

α = 104.72 rad / s²

angular and linear variables are related

a = α r

a = 104.72 0.100

a = 10.47 m / s²

finally we substitute in Newton's second law

F = 1 10⁻³ 10.47

F = 1.047 10⁻² N

8 0

3 years ago

A child drops a ball from a window. The ball strikes the ground in 3.0 seconds. What is the velocity of the ball the instant bef

inessss [21]

Answer:

29.396988 m/s

Explanation:

Really, it depends on where the child is when he drops the ball - e.g., which planet he is on, and his distance from the center of that planet.

I'll assume that the child is on Earth at sea level at the equator, so that his distance from the geocenter is 6378000 meters.

The acceleration, g, is found from

g = GM/r²

G = 6.6743e-11 m³ kg⁻¹ sec⁻²

M = 5.9724e+24 kg

r = 6.378e+6 m

g = 9.799086 m sec⁻²

An approximate answer is found from an equation from constant acceleration kinematics:

v = gt

t = 3.0 sec

v = 29.397259 m/s

Now, the above method is an approximation that makes the technically incorrect assumption that the acceleration of gravity is a constant throughout the entire fall. You get away with it because the drop is very short. In another situation, it might not be. So it would be nice to develop a more accurate method that does not assume constant gravitational acceleration. For that, we begin with the Vis Viva equation:

v = √[GM(2/r − 1/a)]

Here,

a = the semimajor axis of a plunge orbit, which is equal to half of the apoapsis distance of 6378000+h, where

h = the altitude from which the ball is dropped

We can (using some math) develop the following equation:

t − t₀ = √[d/(2GM)] { √(rd−r²) + d arctan √(d/r−1) }

t − t₀ = 3 sec

r = 6378000 meters

d = r + h

Using an iterative method (e.g. Newton's or Danby's), we can determine that the altitude,

h = 44.0954 meters

So,

d = 6378044.09538 meters

a = d/2 = 3189022.04769 meters

Now we can calculate that

v = 29.396988 m/s

This is the more nearly correct answer because it takes into account the variability of the gravitational acceleration during the fall.

5 0

3 years ago

ILI

Nikolay [14]

The original kinetic energy will be 0 J and the final kinetic energy will be 7500 J and the amount of work utilized will be similar to the final kinetic energy i.e., 7500 J.

<u>Explanation:</u>

As it is known that the kinetic energy is defined as the energy exhibited by the moving objects. So the kinetic energy is equal to the product of mass and square of the velocity attained by the car. Thus,

$\text {Kinetic energy}=\frac{1}{2} m v^{2}$

So the initial kinetic energy will be the energy exerted by the car at the initial state when the initial velocity is zero. Thus the initial kinetic energy will be zero.

The final kinetic energy is

$\text {Kinetic energy}=\frac{1}{2} m v^{2}=\frac{1}{2} \times 600 \times 5 \times 5$ = 7500 J

As the work done is the energy required to start the car from zero velocity to 5 m/s velocity.

Work done = Final Kinetic energy - Initial Kinetic energy

Thus the work utilized for moving the car is

Work done = 7500 J - 0 J = 7500 J

Thus, the initial kinetic energy of the car is zero, the final kinetic energy is 7500 J and the work utilized by the car is also 7500 J.

7 0

3 years ago

18. How does magnetic force affect the energy in a system of magnets when the magnets are released and begin to move? a The magn

astra-53 [7]

When the magnets are released and begin to move, the magnetic force changes potential energy into kinetic energy;<u> option D</u>

<h3>What is magnetic force?</h3>

Magnetic force can be defined as the force of attraction or repulsion that is felt or produced between the magnetic poles and electrically charged moving particles.

Magnetic force is the force that exists due to the attractio or repulsion of objects place around the region of space where a maget exerts its force.

When a magnet is released ai a system of magnets and allowed to move it increases the kinetic eergy of the system by converting potential energy to kinetic energy.

Learn more about magnetic force at: brainly.com/question/28989998

#SPJ1

5 0

1 year ago