what are the uses of X-rays.​

Given :

An electron with kinetic energy of 3 MeV.

To Find :

The de-Broglie wavelength for that electron.

Solution :

We know, de-Broglie wavelength for an electron with kinetic energy K.E is given by :

[tex]\lambda = \dfrac{h}{\sqrt{2m(K.E)}}[/tex]

Putting all given values in above equation, we get :

[tex]\lambda = \dfrac{6.626\times 10^{-34}}{\sqrt{2\times 9.1\times 10^{-31}\times 3\times 10^6 \times 1.6\times 10^{-19}}}\\\\\\\lambda = 7.089 \times 10^{-13} \ m[/tex]

Hence, this is the required solution.

Answer:

D

Explanation:

If two unequal forces act in opposite directions, one larger force must cancel out the smaller force,

leaving the net force to be some number in one direction.

Take for example a game of tug-of-war; there are two  OPPOSITE forces (groups of people) acting on the rope, one force is pulling with a force in the negative direction while the other force is pulling in the positive direction.

If the forces on the rope were unequal, then the stronger force (group) will pull everything in their direction.

The same will happen on two unequal forces of opposite directions acting on a wooden block. Therefore, since the resultant force will have a non-zero magnitude and direction, there will be a change in the block's motion and position.

We know, Work done by all the forces is equal to change in potential energy :

[tex]W_{friction} + W_{air} + W_{engine} = \dfrac{(mv_f^2 + mgh_f)}{2}-\dfrac{(mv_i^2+mgh_i)}{2}[/tex]

Here,

[tex]h_i=0\ m\\\\v_i = 0\ m/s[/tex]

Putting all given values, we get :

[tex]W_{friction} + W_{air} + 5.10\times 10^6 = m\dfrac{(v_f^2 + gh_f)}{2}-0\\\\W_{friction} + W_{air} =1.5\times 10^3 \times \dfrac{(24^2 + (9.8\times 2.2\times 10^2))}{2}-5.10\times 10^6\\\\W_{friction} + W_{air} = -3.051\times 10^6\ J[/tex]

Hence, this is the required solution.

Answer:

The lower fixed point, or ice point, is the temperature of pure melting ice at normal atmospheric pressure. The upper fixed point, or steam point, is the temperature of pure boiling water at normal atmospheric pressure.

Explanation:

Answer:

28 m/s

Explanation:

We can use this constant acceleration kinematic equation to find the speed of this beam as it is dropped from 40 m.

Since the object is dropped vertically downwards, we know that the object is in free-fall.

The acceleration of this object is -g, which is -9.8 m/s² since we are making the positive direction upwards and the negative direction downwards.

The initial velocity is 0 m/s since the object is dropped and starts from rest.

The final velocity is what we are trying to solve for.

The displacement in the y-direction is 40 m.

Now we can see which equation contains these 4 variables:

Plug in the known variables.

Simplify this equation.

Take the square root of both sides.

The speed of the 330 kg beam dropped from 40 m is 28 m/s.

Answer:

Explanation:

Given information :

mass = 330kg

height =40m

v = √2gh

Where ;

g = acceleration due to gravity = 9.8 or 10 m/s

h = height

how much total energy of the beam just as it hits the ground =

mgh

[tex]330\times 10\times 40\\\\\\=132000[/tex]

Speed at which  the beam will hit the ground :

[tex]v = \sqrt{2\times 10\times40} \\\\=\sqrt{800}\\\\=20\sqrt{2}\\\\v=28.28427[/tex]

Answer:

  capacitive

Explanation:

In a capacitive circuit, current is proportional to the derivative of the voltage. For a sinusoidal excitation, this means current is at the highest level when voltage is increasing through zero. That is, current leads the voltage.

Answer:

417.5 kg

Explanation:

Since the gravitational for of attraction F, equals the weight of the object W when its close to the earth, F = GMm/R² = W = mg where m = mass of object and g = acceleration due to gravity close to the earth = 9.8 m/s².

g = GM/R² where  g = acceleration due to gravity close to the earth, G = universal gravitational constant = 6.67 × 10⁻¹¹ Nm²/kg², M = mass of earth = 5.927 × 10²⁴ kg and R = radius of earth = 6.4 × 10⁶ m

So, g = GM/R²

= 6.67 × 10⁻¹¹ Nm²/kg² × 5.927 × 10²⁴ kg/(6.4 × 10⁶ m)²

= 39.53 × 10¹³ Nm²/kg ÷ 40.96 × 10¹² m²

= 9.65 N/kg

≅ 9.7 N/kg

= 9.7 m/s²

Since W = 4050 N and W = mg

m = W/g = 4050 N/9.7 m/s²

= 417.53 kg

≅ 417.5 kg

So, the mass of the object is 417.5 kg

Answer:

.

Explanation:

.

Given :

Mass of water, m = 2 grams.

The temperature of water drops from 31 °C to 29 °C .

The specific heat of water is 4.184 J/(g • °C).

To Find :

Amount of heat lost in this process.

Solution :

We know, heat lost is given by :

[tex]Heat\ lost,H = ms( T_f - T_i)\\\\H = 2\times 4.184 \times ( 31 - 29 )\ J\\\\H = 16.736\ J[/tex]

Therefore, amount of heat lost in this process is 16.736 J.

Answer:

150 steps south

Explanation:

250 north 250 back to start then continue south for remainder of 400 steps. 150 south

Answer:d

Explanation:

Answer:

v = 10.85 m/s

Explanation:

We will apply the law of conservation of energy to the skateboarder. Neglecting the frictional effects, the law of conservation of energy can be written as:

[tex]Loss\ in\ Potential\ Energy\ of\ Skateboarder = Gain\ in\ Kinetic\ Energy\ of\ Skateboarder[/tex][tex]mg\Delta h = \frac{1}{2}mv^2\\\\v^2 = 2g\Delta h\\v = \sqrt{2g\Delta h} \\[/tex]

where,

v = velocity of skateboarder = ?

g = acceleration due to gravity = 9.81 m/s²

Δh = change in height = 10 m - 4 m = 6 m

Therefore,

[tex]v = \sqrt{{(2)(9.81\ m/s^2})({6\ m})}}[/tex]

v = 10.85 m/s

Answer:

1. The acceleration would increase.

Explanation:

This is because according to Newton's law, the less mass there is, the more velocity.

Answer:

The speed of the 8-ball is 2.125 m/s after the collision.

Explanation:

Law Of Conservation Of Linear Momentum

The total momentum of a system of masses is conserved unless an external force is applied. The formula for the momentum of a body with mass m and velocity v is

P=mv

If we have a system of masses, then the total momentum is the sum of them all

[tex]P=m_1v_1+m_2v_2+...+m_nv_n[/tex]

If a collision occurs, the velocities change to v' and the final momentum is:

[tex]P'=m_1v'_1+m_2v'_2+...+m_nv'_n[/tex]

In a system of two masses, the law of conservation of linear momentum takes the form:

[tex]m_1v_1+m_2v_2=m_1v'_1+m_2v'_2[/tex]

The m1=0.16 Kg 8-ball is initially at rest v1=0. It is hit by an m2=0.17 Kg cue ball that was moving at v2=2 m/s.

After the collision, the cue ball remains at rest v2'=0. It's required to find the final speed v1' after the collision.

The last equation is solved for v1':

[tex]\displaystyle v'_1=\frac{m_1v_1+m_2v_2-m_2v'_2}{m_1}[/tex]

[tex]\displaystyle v'_1=\frac{0.16*0+0.17*2-0.17*0}{0.16}[/tex]

[tex]\displaystyle v'_1=\frac{0.34}{0.16}[/tex]

[tex]v'_1=2.125\ m/s[/tex]

The speed of the 8-ball is 2.125 m/s after the collision.

Answer:

Normal force

Explanation:

Normal force is the force that surfaces employ so that solid objects are disallowed from passing through each other.

Answer:

D

Explanation:

Answer:

Astronomical Unit = 4.8481×10−6 pc; 1.5813×1.

Or even AU = Equal to

Explanation:

Answer:

marks an important milestone. It's the shortest day of the year and the longest night of the year, and signals a powerful transition point between seasons that is impossible to ignore. ... In Pagan times the winter solstice was referred to as Yule and was a celebration of the Goddess (Moon) energy

Explanation:

Answer:

True

Explanation:

The main differences between a physical property and a chemical property are mentioned below:

A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Physical properties include color, density, hardness, and melting and boiling points.

While A chemical property describes the ability of a substance to undergo a specific chemical change.

Answer:

We could reduce the force or increase the mass of the object.

Explanation:

Using the definition of force, according to Newton's second law,  (F = ma) the acceleration is directly proportional to the force and inversely proportional to the mass. Therefore, if we want to reduce the acceleration of an object we have two options:

In both cases a will decrease.  

I hope it helps you!

Answer:

The value is [tex]\lambda = 0.335 \ m[/tex]  

Explanation:

From the question we are told that

     The length of the string is  [tex]l = 0.67 \ m[/tex]

      The mass is  [tex]m = 2.0 \ g = 0.002 \ kg[/tex]

      The frequency produced at  fourth harmonic vibration(i.e n =4 )  is  [tex]f = 700 \ Hz[/tex]

  Generally the wavelength of the string is  mathematically represented as

            [tex]\lambda = \frac{ 2L }{n }[/tex]

=>          [tex]\lambda = \frac{ 2 * 0.67 }{ 4 }[/tex]  

=>          [tex]\lambda = 0.335 \ m[/tex]  

Answer:

The velocity of the astronaut is approximately 0.0008571 m/s

Explanation:

The mass of the the wrench, m₁ = 4 grams = 0.004 kg

The velocity of the wrench, v₁ = -15 m/s

The mass of the astronaut, m₂ = 70 kg

The velocity of the astronaut = v₂

Whereby the astronaut and the wrench were initially at rest, we have;

The total initial momentum = 0 kg·m/s

The total final momentum = m₁ × v₁ + m₂ × v₂ = 0.004 kg × (-15 m/s) + 70 kg × v₂

By the conservation of momentum principle, we have;

The total initial momentum = The total final momentum

Therefore, we have;

0 kg·m/s = 0.004 kg × (-15 m/s) + 70 kg × v₂

Which gives;

0.004 kg × (-15 m/s) = 70 kg × v₂

70 kg × -v₂ = 0.004 kg × (-15 m/s)

-v₂ = 0.004 kg × (-15 m/s)/(70 kg) ≈ -0.0008571 m/s

-v₂ ≈ -0.0008571 m/s

v₂ ≈ 0.0008571 m/s

The velocity of the astronaut = v₂ ≈ 0.0008571 m/s

Answer:

i dont know the answer sorry have a good day

Explanation:

hsjsjdkdkdkdkdkdk

Answer:3.4 miles west

Explanation:

Answer:

1.7 g/cm³

Explanation:

Given that:

Density of substance = 3.4 g/cm³

Relative density to another substance = 2

Density of second substance=?

Let density of second substance = x

Relative density = density of substance / density of second substance

Relative density = density of substance / x

2.0 = 3.4g/cm³ / x

2 * x = 3.4 g /cm³

x = 3.4 g/cm³ ÷ 2

x = 1.7 g/cm³

Answer: wavelength is the length of the wave, example the length of a sound wave.

Velocity is also known as speed.

Explanation:

Starting from rest, the wheel accelerates to an angular velocity of

ω = (2.52 rad/s²) (7.03 s) ≈ 17.7 rad/s

then undergoes a new acceleration α until it comes to a rest. It does so in 11.9 revolutions, or with an angular displacement of (11.9 rev) • (2π rad/rev) = 23.8π rad. So α satisfies

0² - ω² = 2 α (23.8π rad)

α = - ω² / (47.6π rad)

α ≈ -2.10 rad/s²

Answer:

true

Explanation:

i think it's true because I took a quiz on this

Answer:

is changing in direction, but constant in magnitude

Explanation:

This question is a bit tricky since the velocity of the satellite is changing, but the speed is constant.

Speed is simply a measure of how fast you are going. It doesn't matter where you're going, just how quickly.

Velocity, on the other hand, does care about which direction you're going. For example, it could be then when you travel right, your velocity is positive, and when you travel left, your velocity is negative. This is the similar for a 2D shape like a circular orbit

Since we know velocity is changing, there must be acceleration which changes that velocity (since acceleration is the change in velocity: going from 0 to 60 mph, for example)

Thus, with a non-zero net acceleration, we know that there must be a force that is changing in direction, but constant in magnitude (since the orbit is a circle, and always attracted to the center of the Earth at equal distance).

Explanation:

Accordibg to Hooke's law ,

F=-kx

the minus sign indicates that the force exerted by the spring is opposite to that of extension and the relation between force and extension is a linear one so in the graph it wll pass through the origin and x=0 F=0 and the k (spring constant) will be a constant