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4 years ago

Jake drops a book out of a window from a height of 10 meters. At what velocity does the book hit the ground?

1 answer:

8 0

G = 9.81 m/sec^2) g = 9.81 $\frac{meters}{ second^{2} }$

Solving for velocity : 

$velocity^{2}$ = 2gh 
v = $2gh^{ \frac{1}{2} }$
v = (2 x 9.81 x 10)^1/2 
v = 196.2 m/sec (answer)

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A ladybug sits at the outer edge of a turntable, and a gentleman bug sits halfway between her and the axis of rotation. The turn

Cerrena [4.2K]

Answer:

e. Not enough information to determine

Explanation:

This question is incomplete. Here is the complete question with my solution afterwards;

A ladybug sits at the outer edge of a turntable, and a gentleman bug sits halfway between her and the axis of rotation. The turntable (initially at rest) begins to rotate with its rate of rotation constantly increasing.

What is the first event that will occur?(Assume non-zero frictional force and the same coefficients of friction for both bugs.)

a. The ladybug begins to slide

b. The gentleman bug begins to slide

c. Both bugs begin to slide at the same time

d. Nothing ever happens

e. Not enough information to determine

The centripetal force acting on a rotating body or bugs can be written as,

$F=mrw^2$

$m=$ mass of the corresponding bugs

$r=$ corresponding radial distance of each bug

$w=$ angular speed of the turntable

The centripetal force tries to slide the bugs in an outward direction and it is directly proportional to the products of its mass and radial distance from the axis of rotation of the turntable

$F$ ∝ $mr$

Since the radial distance from the axis of rotation of the turntable for each bug is given, but the mass is not given, the given information is therefore not enough to determine which bugs will slide first.

Option "e" is correct.

7 0

3 years ago

Read 2 more answers

What is the frequency and wavelength, in nanometers, of photons capable of just ionizing nitrogen atoms?

nika2105 [10]

Answer:

The frecuency and wavelength of a photon capable to ionize the nitrogen atom are ν = 3.394×10¹⁵ s⁻¹ and λ = 88.31 nm.

Explanation:It is possible to know what are the frequency and wavelength of a photon capable to ionize the nitrogen atom using the equation of the energy of a photon described below.

E = hc/λ (1)

Where h is the Planck constant, c is the speed of light and λ is the wavelength of the photon.

But first, it is neccesary to know the ionization energy of the nitrogen atom. The ionization energy is the energy needed to remove an electron from an atom, for the Nitrogen atom it will lose an electron of its outer orbit from the nucleus, farther snuff, so the electric force is weaker. Experimentally, it is known that it has a value of 14.04 eV. This value is easy to found in a periodic table.

So the nitrogen atom will need a photon with the energy of 14.04 eV to remove the electron from its outer orbit.

Replacing the Planck constant, the speed of light and the energy of the photon in the equation 1, the wavelength can be calculated:

λ = hc/E (2)

Where h = 6.626×10⁻³⁴ J.s and c = 3.00×10⁸ m/s

But the Planck constant can be expressed in electron volts:

1 eV = 1.602 x 10⁻¹⁹ J

h = 6.626x10⁻³⁴ J/1.602x10⁻¹⁹ J . eV .s

h= 4.136x10⁻¹⁵ eV.s

Now, it is convenient to express the speed of light in nanometers:

1nm = 1x10⁻⁹ m

c = 3.00x10⁸ m/ 1x10⁻⁹ m

c = 3x10¹⁷ nm/s

Substituting in equation 2:

λ = (4.136x10⁻¹⁵ eV.s)(3x10¹⁷ nm/s)/14.04 eV

λ = 1240 eV. nm/ 14.04 eV

λ = 88.31 nm

The frenquency is calculated using the equation 2 in the following way:

E = hν (3)

Where ν is the frecuency

ν = E/h

ν = 14.04 eV/4.136×10⁻¹⁵ eV.s

ν = 3.394×10¹⁵ s-1

So the frecuency of a photon, capable to ionize the nitrogen atom, will be 3.394×10¹⁵ s⁻¹ and its wavelength 88.31 nm.

4 0

4 years ago

What is the formula for speed

maw [93]

The formula for speed is distance traveled divided by time

3 0

3 years ago

Read 2 more answers

A rifle that shoots bullets at 471 m/s is to be aimed at a target 46.4 m away. If the center of the target is level with the rif

Genrish500 [490]

Answer:

The equation that will express this result os

h = 0 = vy t - 1/2 g t^2 so the net height traveled by the bullet is zero

vy t = 1/2 g t^2

vy = 1/2 g t

vy = 1/2 * 9.8 * t you could use -9.8 to indicate vy and g are in different directions

tx = sx/ vx = 46.4 / 471 = .0985 sec time to travel up and down to original height

th = .0985 / 2 = .0493 sec time to reach maximum height

vy = g ty = 9.8 * .0493 sec = .483 m/s initial vertical speed

Sy = vy t - 1/2 g t^2 = .483 * .0493 - 1.2 9.8 (.0493^^2)

Sy = .0238 - 4.9 ( .0493)^2 = .0238 - .0119 = .0119 m

Height to which bullet will rise - if the gun is aimed at this height then in .0985 seconds the bullet will fall to zero height

Check: .483 / 9.8 = .0493 time to reach zero vertical speed

total travel time = 2 * .0493 = .0986 sec

471 * .0986 = 46.4 m total distance traveled by bullet

7 0

3 years ago

Light waves travel most slowly through a ____ A) gas B) solid C) liquid

WITCHER [35]

Answer:

Liquid

Explanation: It can't be gas because gases are all around us and we can still see light. For solids it can't even move through a solid. Ex: If you're in a solid dome made of rock you can't get any light through. Let me know if I'm right!

3 0

4 years ago

Read 2 more answers