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3 years ago

An automobile travels on a straight road at 30 km/h How long will it take to travel 40 km

Physics

1 answer:

Anna [14]3 years ago

4 0

Answer:

the time taken for the automobile to travel the given distance is 80 mins.

Explanation:

Given;

speed of the automobile, v = 30 km/h

distance traveled by the automobile, x = 40 km

The time taken for the automobile to cover the given distance is calculated as;

time = distance / speed

time = 40 / 30

time = 1.3333 hours = 1.3333 hr x 60mins/hr = 80 mins

Therefore, the time taken for the automobile to travel the given distance is 80 mins.

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Tidal forces are gravitational forces exerted on different parts of a body by a second body. Their effects are particularly visi

Nastasia [14]

Answer:

B) True.

Explanation:

In this exercise to answer the statements we must calculate the force on the earth by the two bodies.

In both cases, the law of universal gravitation describes the process.

F = G m₁ m₂ / r²

Let's calculate each force

- bodies Moon - Earth

Let's call m₁ the mass of the earth (m₁ = me), m₂ the mass of the moon (m₂ = m), the distance from the earth to the moon is r₁ = 3.84 10⁸m and the radius of the earth is re. The force on the tide that is a body on the surface of the Earth have a distance

R₁ = r₁ -re

R₁ = 3.84 10⁸ - 6.37 10⁶

R₁ = 3.77 10⁸ m

Let's calculate

F₁ = G me m / R₁²

F₁ = (G me) 7.36 10²² / (3.77 10⁸)²

F₁ = (G me) 5.2 10⁵

- bodies Earth -Sun

Let's call the mass of the sun M (m2 = M) the distance from the sun to the earth is 1.5 10¹¹ m, so the distance to the surface of the earth

R₂ = r₂ - re

R₂ = 1.5 10¹¹ - 6.37 10⁶

R₂ = 1.5 10¹¹ m

The radius of the earth is too small compared to the earth-sun distance

Let's calculate

F₂ = G me M / R₂²

F₂ = (G me) 1.99 10³⁰ / (1.5 10¹¹)²

F₂ = (G me) 8.8 10⁷

Let's see the statements:

A) False. It´s oppsote

B) True. In the previous part it has a differentiated 10² orders of magnitude

C) False. We saw that they are very different

4 0

3 years ago

Read 2 more answers

Definition of displacement

lesya [120]

The moving of something from its place or position.
"vertical displacement of the shoreline"
the removal of someone or something by someone or something else that takes their place.
"males may be able to resist displacement by other males"

5 0

3 years ago

What is the order of magnitude of the speed of light

iren2701 [21]

Answer:

The order of magnitude of speed of light in S.i. units is 8. Therefore c=3×10^8 meter / second.

Explanation:

6 0

3 years ago

A photoelectric effect experiment finds a stopping potential of 1.93 V when light of wavelength 200 nm is used to illuminate the

PSYCHO15rus [73]

a) zinc

The equation of the photoelectric effect is:

$E=\phi + K$ (1)

where

E is the energy of the incident light

$\phi$ is the work function

$K$ is the maximum kinetic energy of the emitted photoelectrons

Here the wavelength of the incident light is

$\lambda=200 nm = 2\cdot 10^{-7} m$

so the energy of the light is

$E=\frac{hc}{\lambda}=\frac{(6.63\cdot 10^{-34} Js)(3\cdot 10^8 m/s)}{2\cdot 10^{-7} m}=9.95\cdot 10^{-19} J$

Converting into electronvolts,

$E=\frac{9.95\cdot 10^{-19}}{1.6\cdot 10^{-19} J/eV}=6.22 eV$ (2)

The stopping potential is the potential needed to stop the photoelectrons with maximum kinetic energy: so, the electrical potential energy corresponding to the stopping potential (V=1.93 V) must be equal to the maximum kinetic energy of the photoelectrons,

$U=q V = K$

and since the charge of the electron is

1 q = 1 e

We have

$K=(1 e)(1.93 V)=1.93 eV$ (3)

Combining (1), (2) and (3), we find the work function of the material:

$\phi = E-K=6.22 eV-1.93 eV=4.29 eV$

So, the cathode is most likely made of zinc, which has a work function of 4.3 eV.

b) The stopping potential does not change

As we said in part A), the stopping potential is proportional to the maximum kinetic energy of the photoelectrons, K.

The intensity of light is proportional to the number of photons that hit the surface of the metal. However, the energy of these photons does not depend on the intensity, but only on the frequency of the light.

Therefore, the energy of the photons (E) does not change when the intensity of light is doubled. Also, the work function $\phi$ does not change: this means that the maximum kinetic energy of the photoelectrons, K, does not change, and so the stopping potential remains the same.

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3 years ago

In connective tissue, the role of elastic fibers is to __________.

blagie [28]

The role of elastic fiber is to keep the tissue length(or elasticity). That means if the tissue is stretched the elastic fiber will exert force to make it back into the normal length. This fiber can be found<span> in skin and lack of it will make wrinkle. Other connective tissue would be collagen which will give strength</span>

6 0

3 years ago