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3 years ago

What acceleration is caused by Earth's gravity near the surface?

Physics

1 answer:

suter [353]3 years ago

6 0

Answer:

9.8 meters is the acceleration of gravity. This is near the surface of the Earth.

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Which statement best describes how waves carry energy?

ratelena [41]

Correct answer choice is :

A) Energy moves from one place to another through the wave.

Explanation:

Waves can carry energy over a range without moving matter the complete distance. For instance, an ocean wave can move many kilometers without the water itself traveling many kilometers. The water moves up and down a motion recognized as a disturbance. A wave brings its energy without carrying matter. Waves are observed to travel through an ocean or lake, yet the water perpetually reverts to its rest state. Energy is carried through the medium, yet the water particles are not carried.

7 0

3 years ago

Read 2 more answers

Can mechanical energy be used to do work?

Lady_Fox [76]

Answer:

Mechanical Energy as the Ability to Do Work An object that possesses mechanical energy is able to do work. In fact mechanical energy is often defined as the ability to do work. Any object that possesses mechanical energy.

Explanation:

7 0

1 year ago

Calculate the energy in electron volts of X-rays that have a frequency of 3.00 x 100 Hz.

inn [45]

Answer:

E = 124 eV

Explanation:

Given,

The frequency of the X-rays, ν = 3.0 x 10¹⁰ Hz

The formula for calculating the energy of the electromagnetic waves of a single photon of having frequency 'ν' is given by the relation

E = hν joules

Where,

h - Planck's constant (6.626 x 10⁻³⁴ Js)

Substituting the values in the above equation

E = 6.626 x 10⁻³⁴ Js x 3.0 x 10¹⁰ Hz

= 1.9878 x 10⁻²³ J

Converting it into eV

E = 1.9878 x 10⁻²³ x 6.242 x 10¹⁸ eV

= 124 eV

Therefore, the energy in electron volts of X-rays is, E = 124 eV

8 0

2 years ago

A box slides down a frictionless ramp.if it starts at rest, what is it’s speed at the bottom?

zhenek [66]

8.854 m/s is the speed of the box after it reaches bottom of the ramp.

<u>Explanation</u>:

From the figure we came to know that height of the block is 4 m.

We know that,

Total "initial energy of an object" = Total "final energy of an object "

Total "initial energy of an object" is = "sum of potential energy" and "kinetic energy" of an object at its initial position.

$\text { "g" acceleration due to gravity is } 9.8 \mathrm{m} / \mathrm{s}^{2}$

$\text { Total initial energy }=\mathrm{m} \times \mathrm{g} \times \mathrm{h}_{\mathrm{i}}+\frac{1}{2} \mathrm{m} v_{i}^{2}$

Initial velocity is “0” as the object does not have starting speed

$\text { Height of the block where the object is placed initially }\left(h_{i}\right) \text { is } 4 \mathrm{m} \text { . }$

$\text { Total initial energy }=\mathrm{m} \times 9.8 \times 4+\frac{1}{2} \mathrm{m} 0^{2}$

Total initial energy = 39.2 × m

$\text { Total final energy }=\mathrm{m} \times \mathrm{g} \times \mathrm{h}_{\mathrm{f}}+\frac{1}{2} m v_{f}^{2}$

$\text { We need to find final velocity } v_f$

$\text { Height of the block where the object is travelled to bottom (h_) is } 0 \mathrm{m} \text { . }$

$\text { Total final energy }=\mathrm{m} \times 9.8 \times 0+\frac{1}{2} m v_{f}^{2}$

Now, Total initial energy of an object = Total final energy of an object

$39.2 \times \mathrm{m}=0.5 \mathrm{m} v_{f}^{2}$

$\frac{39.2}{0.5}=v_{f}^{2}$

$v_{f}^{2}=78.4$

$v_{f}=\sqrt{78.4}$

$v_{f}=8.854 \mathrm{m} / \mathrm{s}$

Final speed is 8.854 m/s.

3 0

3 years ago

An electron travels west to east with a kinetic energy of 10 keV. The Earth's magnetic field in Pittsburgh is 19,911.5 nT in the

ch4aika [34]

Explanation:

It is given that,

Kinetic energy of the electron, $E_k=10\ keV=10^4\ eV=1.6\times 10^{-15}\ J$

Let the east direction is +x direction, north direction is +y direction and vertical direction is +z direction.

The magnetic field in north direction, $B_y=19911.5\ nT$

The magnetic field in west direction, $B_x=-3257.1\ nT$

The magnetic field in vertical direction, $B_z=48381.8 \ nT$

Magnetic field, $B=(-3257.1i+19911.5j+48381.8k)\ nT$

Firstly calculating the velocity of the electron using the kinetic energy formulas as :

$E_k=\dfrac{1}{2}mv^2$

$v=\sqrt{\dfrac{2E_k}{m}}$

$v=\sqrt{\dfrac{2\times 1.6\times 10^{-15}}{9.1\times 10^{-31}}}$

$v=5.92\times 10^7 i\ m/s$ (as it is moving from west to east)

The force acting on the charged particle in the magnetic field is given by :

$F=q(v\times B)$

$F=1.6\times 10^{-19}\times (5.92\times 10^7 i\times (-3257.1i+19911.5j+48381.8k)\times 10^{-9})$

Since, $i\times j=k\ \\j\times k=i\\k\times i=j$

And, $i\times i=j\times j=k\times k=0$

$F=1.6\times 10^{-19}\times [1178 k-2864.20j]$

$|F|=1.6\times 10^{-19}\times \sqrt{1178^2+2864.20^2}$

$F=4.95\times 10^{-16}\ N$

(b) Let a is the acceleration of the electron. It can be calculated as :

$a=\dfrac{F}{m}$

$a=\dfrac{4.95\times 10^{-16}}{9.1\times 10^{-31}}$

$a=5.43\times 10^{14}\ m/s^2$

Hence, this is the required solution.

4 0

2 years ago