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3 years ago

A motor pulls an 800 kg roller coaster train to the top of a 70 m hill. What is the change in the potential energy of the cars?

Physics

1 answer:

Angelina_Jolie [31]3 years ago

5 0

Answer:

548800J

Explanation:

Given parameters:

Mass of roller coaster = 800kg

Height of hill = 70m

Unknown:

Change in potential energy = ?

Solution:

The change in potential energy is the difference between the potential energy at the bottom and at the top.

Potential energy at the bottom is 0J

So;

Change in potential energy = mgh - 0

m is the mass, g is the acceleration, h is the height

Change in potential energy = 800 x 9.8 x 70 = 548800J

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A force that results from charged particles is called?

olchik [2.2K]

A force that results from charged particles is called "electrostatic force".

Hope this helps!

-Thanks!

-Charlie

7 0

3 years ago

Read 2 more answers

A photograph is taken by letting light fall on a light-sensitive medium, which then records the image onto that medium. True or

Jet001 [13]

Answer;

The above statement is true.

-A photograph is taken by letting light fall on a light-sensitive medium, which then records the image onto that medium.

Explanation;

-A photograph is created when light is allowed to fall on a light-sensitive medium. The pattern of light creates an image that is recorded by the photographic device. How light or dark a photograph is depends on how much light was allowed to fall on the light-sensitive medium.

-A camera is a light-tight box that contains a light-sensitive material or device and a way of letting in a desired amount of light at particular times to create an image on the light-sensitive material.

6 0

3 years ago

An electron is released from rest at a distance of 6.00 cm from a proton. If the proton is held in place, how fast will the elec

lana66690 [7]

Answer:

91.87 m/s

Explanation:

Given:

x = initial distance of the electron from the proton = 6 cm = 0.06 m

y = initial distance of the electron from the proton = 3 cm = 0.03 m
u = initial velocity of the electron = 0 m/s

Assume:

m = mass of an electron = $9.1\times 10^{-31}\ kg$
v = final velocity of the electron
e = magnitude of charge on an electron = $1.6\times 10^{-19}\ C$

p = magnitude of charge on a proton = $1.6\times 10^{-19}\ C$

We know that only only electric field due to proton causes to move from a distance of 6 cm from proton to 3 cm distance from it. This means the electric force force does work on the electron to move it from one initial position to the final position which is equal to the change in potential energy of the electron due to proton.

Now, according to the work-energy theorem, the total work done by the electric force on the electron due to proton is equal to the kinetic energy change in it.

$\therefore \textrm{Kinetic energy change}= \textrm{Change in potential energy}\\\Rightarrow \dfrac{1}{2}m(v^2-u^2)= \dfrac{kpe}{y}-\dfrac{kpe}{x}\\\Rightarrow \dfrac{1}{2}m(v^2-(0)^2)= \dfrac{kpe}{0.03}-\dfrac{kpe}{0.06}\\\Rightarrow \dfrac{1}{2}mv^2= \dfrac{100kpe}{3}-\dfrac{100kpe}{6}\\\Rightarrow \dfrac{1}{2}mv^2= \dfrac{100kpe}{6}\\$

$\Rightarrow v^2= \dfrac{100kpe\times 2}{6m}\\\Rightarrow v^2= \dfrac{100kpe}{3m}\\\Rightarrow v^2= \dfrac{100\times 9\times 10^9\times 1.6\times 10^{-19}\times 1.6\times 10^{-19}}{3\times 9.1\times 10^{-31}}\\\Rightarrow v^2=8.44\times 10^3\\\Rightarrow v=91.87\ m/s\\$

Hence, when the electron is at a distance of c cm from the proton, it moves with a velocity of 91.87 m/s.

8 0

3 years ago

Harry Potter is chasing his nemesis Draco Malfoy during a quidditch match. Initially, Harry is 35m behind Draco, who has just sp

Sophie [7]

Answer:

the acceleration of harry is equal to 66.126 m/s²

Explanation:

given,

harry is 35 m behind Draco

speed of Draco = 40 m/s

original speed of harry = 50 m/s

acceleration = ?

time taken by the Draco

t = $\dfrac{r}{u} =\dfrac{75}{40}$

t = 1.875 s

distance covered by Harry

d = 35 + 175 = 210 m

to calculate the acceleration of harry

$s = u t+ \dfrac{1}{2}at^2$

$210 = 50\times 1.875+ \dfrac{1}{2}\times a\times 1.875^2$

a × 3.516 × 0.5 = 116.25

a = 66.126 m/s²

hence, the acceleration of harry is equal to 66.126 m/s²

3 0

3 years ago

In the photoelectric effect, the greater the frequency of the illuminating light, the greater the:_______

TEA [102]

Answer:

B. Maximum velocity of ejected electrons.

Explanation:

The ejection of electrons form a metal surface when the metal surface is exposed to a monochromatic electromagnetic wave of sufficiently short wavelength or higher frequency (or equivalently, above a threshold frequency), which leads to the enough energy of the wave to incident and get absorbed to the exposed surface emits electrons. This phenomenon is known as the photoelectric effect or photo-emission.

The minimum amount of energy required by a metal surface to eject an electron from its surface is called work function of metal surface.

The electrons thus emitted are called photo-electrons.

The current produced as a result is called photo electricity.

Energy of photon is given by:

$E=h.\nu$

where:

h = Planck's constant

$\nu=$ frequency of the incident radiation.

8 0

3 years ago