a stone is thrown vertically upwards with a velocity of 20 m per second what will be its velocity when it reaches a height of 10.2 m​

The comparison of the speeds and kinetic energy of the identical balls are as follows

The speed and the kinetic energy of the first and fourth ball are equal, while the speed and kinetic energy of the second and third balls are equal

The reason for the above comparison results areas follows;

Known parameters;

First ball is thrown straight up

Second ball is thrown 30° above the horizontal

Third ball it thrown 30° below the horizontal

The fourth ball is thrown straight down

Unknown:

Comparison of the speed and kinetic energy of the four balls

Method:

The kinetic energy, K.E. = (1/2) × m × v²

The velocity of the ball, v = u × sin(θ)

Where;

u = The initial velocity of the ball

θ = The reference angle

θ = 90°

∴ [tex]v_y[/tex] = u

The final velocity of the ball as it strikes the ground is v₂ = u² + 2gh

Where;

h = The height of the cliff

∴ Kinetic energy of first ball, K.E.₁ = (1/2) × m × (u₁² + 2gh)²

K.E. = (1/2) × m × ((u×sin30)² + 2·g·h)² = K.E. = (1/2) × m × ((0.5·u)² + 2·g·h)²

Kinetic energy  K.E.₂ = (1/2) × m × ((0.5·u₂)² + 2·g·h)²

K.E. = (1/2) × m × ((u×sin30)² + 2·g·h)² = K.E. = (1/2) × m × ((0.5·u)² + 2·g·h)²

Kinetic energy K.E.₃ = (1/2) × m × ((0.5·u₃)² + 2·g·h)²

Kinetic energy K.E.₄ = (1/2) × m × (u₄² + 2gh)²

Therefore, as the ball strike the ground, the speed and the kinetic energy of the first and fourth ball are equal, while the speed and kinetic energy of the second and third balls are equal

u₁ = u₄, K.E₁ = K.E.₄, u₂ = u₃, K.E₂ = K.E.₃

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Answer:

I THINK C

Explanation:

BECAUSE A Light Emitting Diode (LED) glows even when a weak electric current passes through it.

Answer:

rock go down

Explanation:

what comes up must come down.

Answer:

[tex]0.2677\ \text{V/m}[/tex]

Explanation:

A = Area of loop = [tex]0.129\times0.402[/tex]

B = Magnetic field = [tex]0.888\ \text{T}[/tex]

t = Time taken = [tex]0.172\ \text{s}[/tex]

Electric field is given by

[tex]E=B\dfrac{dA}{dt}\\\Rightarrow E=0.888\times\dfrac{0.129\times 0.402}{0.172}\\\Rightarrow E=0.2677\ \text{V/m}[/tex]

The emf induced is [tex]0.2677\ \text{V/m}[/tex].

Answer:

The wavelength is "[tex]=16.5675\times 10^{-18} \ m[/tex]".

Explanation:

Given:

Mass,

m = [tex]1\times 10^{-11} \ g[/tex]

Speed,

V = [tex]0.400 \ cm/s[/tex]

or,

  = [tex]0.4\times 10^{-2}[/tex]

According to De Broglie,

The wavelength will be:

⇒ [tex]\lambda = \frac{h}{mV}[/tex]

      [tex]=\frac{6.627\times 10^{-34}}{1\times 10^{-11}\times 10^{-3}\times 0.4\times 10^{-2}}[/tex]

      [tex]=16.5675\times 10^{-18} \ m[/tex]

So, blood cells move these wavelength.

Answer:

h = change in vertical position (height)

has units of distance.

Explanation:

The equation below can be used to calculate a change in gravitational potential energy then the units used for the height would be meters.

The sum of all the energy in motion (total kinetic energy) and all the energy that is stored in the system (total potential energy) is known as mechanical energy.

As given in the problem, the equation below can be used to calculate a change in gravitational potential energy, the units used for the height of the object would be in meters, which is the SI unit of the length

The gravitational potential energy = mass×acceleration ×height

Thus, the unit of height used in the gravitational potential energy formula would be meter.

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9514 1404 393

Answer:

  1.114 kg/m³

Explanation:

The total mass of the air in the balloon and the balloon + cargo will be the mass of the displaced air. If d is the density of the air in the balloon, then we have ...

  2910d +308 = 2910×1.22

Solving for d, we find ...

  2910d = 2919(1.22) -308

  d = 1.22 -308/2910

  d ≈ 1.114 . . . kg/m³

The density of the hot air is about 1.114 kg/m³.

Question:- A scientist who studies the tiny microorganisms of the environment

Explanation:-

Microbiologist means a person who studies micro sized living organisms

Microbiologist word is combination of two words Micro and biologist

Answer:

microbiologist i think

hope it helps

please mark Brainliest if you think the answer is correct

Explanation:

We know that the tangent velocity is 8.1 m/s. We also know that the tangent velocity can be written in the following way:

Vt = ωr with ω being the angular velocity.

We now calculate ω:

ω = Vt/r = 8.1 m/s / 27m = 0.3 rad/s

Now that we have ω we can calculate the centripetal aceleration:

a = ω^2 * r = ( 0.3 )^2 * 27 = 2.43 m/s^2

The strength of the thrust is 122 newtons.

The motion of the rocket is described by the second Newton's law, whose model is shown below:

[tex]\Sigma F = F - D = m\cdot a[/tex] (1)

Where:

If we know that [tex]D = 90\,N[/tex], [tex]m = 8\,kg[/tex] and [tex]a = 4\,\frac{m}{s^{2}}[/tex], then the strength of the thrust is:

[tex]F = D + m\cdot a[/tex]

[tex]F = 90\,N + (8\,kg)\cdot \left(4\,\frac{m}{s^{2}} \right)[/tex]

[tex]F = 122\,N[/tex]

The strength of the thrust is 122 newtons.

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Answer:

Ecologist.

Your answer is Ecologist.

(Ecologist) is a scientist who studies the whole environment as a working unit.

The name and strength of the force holding the block up is 50 N upward - Normal force.

The given parameters:

The weight of the block acting downwards due to gravity is calculated as follows;

W = mg

where;

W = 5 x 10

W = 50 N (downwards)

Since the block is at rest, an a force equal to the weight of the block must be acting upwards. This force is known as normal reaction.

Fₙ = 50 N (upwards)

Thus, the name and strength of the force holding the block up is 50 N upward - Normal force.

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The block will remain on the table because the normal force balances with the weight of the block. The correct answer is  50 N upward normal force

From the diagram shown a 5.00-kilogram block at rest on a horizontal, frictionless table. The weight of the block will act downward which will be

Weight W = mg

let g = 10 m/[tex]s^{2}[/tex]

W = 5 x 10

W = 50 N

The block will also produce an equal but in opposite direction of a normal force which is equal to the weight of the block. That is,

Normal force N = 50 N

The block will remain on the table because the normal force balances with the weight of the block.    

Therefore, the correct name and strength of the force holding the block up is 50 N upward normal force.

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Answer:

D.) Do clones have the same rights as humans?

Explanation:

This is the only option choice that relates to ethics, more specifically, bioethics. The rest of the answer choices look either seek for scientific explanations on cloning itself or the implications of clothing. Only answer choice D relates to ethics.

Answer:

B

Explanation:

P1/P1 = 40/20

=2

Answer:

The distance of man from the mirror is 3 m

Refer to the attachment

[tex]\Large\textsf{Hope \: It \: Helped}[/tex]

The distance of the man from the mirror is 3m

From the characteristics of image formed in a plane mirror,

⇒ From the last point,

⇒ From the question,

Hence, The distance of the man from the mirror is 3m

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Answer:

2

Explanation:

pulling force because of it force

Answer:

5.9 cm

Explanation:

f: frequency of oscillation

frequency of oscillationk: spring constant

frequency of oscillationk: spring constantm: the mass

[tex]f = \frac{1}{2\pi} \sqrt{ \frac{k}{m} } [/tex]

in this problem we know,

F= 1.4 Hz

m= 0.26 kg

By re-arranging the formula we get

[tex]k = {(2\pi \: f )}^{2} m = {(2\pi(1.4hz))}^{2} 0.26kg = 20.1 \frac{n}{m} [/tex]

The restoring force of the spring is:

F= kx

where

F= 1.2 N

k= 20.1 N/m

x: the displacement of the block

[tex]x = \frac{f}{k} = \frac{1.2 \: n}{20.1 \frac{n}{m} } = 0.059m \: = 5.9 \: cm[/tex]

Answer:

the correct one is C

Explanation:

To find the answer, let's propose the solution of the problem

We create a system formed by the child and the platform so that all the forces have been internal and the angular momentum is conserved.

Initial instant. Before starting to walk

          L₀ = 0

Final moment. After the child is walking

          L_f = I₁ w₁ + m r v₂

where index 1 is used for the platform and index 2 for the child

linear and angular velocity are related

          v₂ = w₂ r

angular momentum is conserved

          0 = I₁ w₁ + m r (w₂ r)

          w₁ =  [tex]- \frac{m r^2}{I1} \ w_2[/tex]

the moment of inertia of the platform bringing it closer to a disk or cylinder

         I₁ = [tex]\frac{1}{2}[/tex] M r²  

sustitute

          w₁ = [tex]- \frac{2 m }{M} \ w_2[/tex]

          W₁ = - [tex]- \frac{2 40}{30} \ w_2 = - \frac{8}{3} \ w_2[/tex]

from here we can see that the platform and the child rotate in the opposite direction and with different angular speeds

when examining the answers the correct one is C

Answer:

Explanation:

relative to the ground the boy moves in a counter clockwise motion , now the boy and the wheel are one system

so by conservation of angular momentum their net sum of angular momentum relative to a point outside the system(say ground) should be zero

so the wheel moves in a clockwise direction , their angular velocity may or may not be same depending on I. so option D is wrong

option B is wrong because relative to ground their angular momentum should be equal and opposite

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Answer:

15.88°C I am not 100% sure this is right but I am 98% sure this IS right

Answer:

    wo = 18.75 rev / s

Explanation:

This is an exercise in endowment kinematics, it indicates that the final angular velocity is w_f = 109 rad / s, the time to reach this velocity is t = 1.87 s and the deceleration a = 4.7 rad / s²

         w_f = w₀ - a t

         w₀ = w_f + a t

         w₀ = 109 + 4.7 1.87

         w₀ = 117.8 rad / s

let's reduce to revolutions / s

         w₀ = 117.8 rad / s (1 rev / 2pi rad)

         w₀ = 18.75 rev / s

Answer:  

Hence the answer is E inside [tex]= KQr_{1} /R^{3}[/tex].

Explanation:  

E inside [tex]= KQr_{1} /R^{3}[/tex]  

so if r1 will be the same then  

E  [tex]\begin{bmatrix}Blank Equation\end{bmatrix}[/tex] proportional to 1/R3  

so if R become 2R  

E becomes 1/8 of the initial electric field.

Answer:

The electric field is E/8.

Explanation:

The electric field due to a solid sphere of uniform charge density inside it is given by

[tex]E =\frac{\rho r}{3}[/tex]

where, [tex]\rho[/tex] is the volume charge density and r is the distance from the center.

For case I:

[tex]\rho = \frac{Q}{\frac{4}{3}\pi R^3}[/tex]

So, electric field at a distance r is

[tex]E = \frac { 3 Q r}{3\times 4\pi R^3}\\\\E = \frac{Q r}{4\pi R^3}[/tex]

Case II:

[tex]\rho = \frac{Q}{\frac{4}{3}\pi 8R^3}[/tex]

So, the electric field at a distance r is

[tex]E' = \frac { 3 Q r}{3\times 32\pi R^3}\\\\E' = \frac{Q r}{8\times 4\pi R^3}\\\\E' = \frac{E}{8}[/tex]

Answer:

Light takes less time than sound.

Explanation:

Let's say, the teacher and the student are at a distance "d" from each other.

The medium around them would be air.

And,

The speed of light in air is approx. 3× 10⁸ m/s

while, the speed of sound in air is approx. 330 m/s

We have a formula that establishes the relation between speed, distance and time.

[tex] \boxed{ \mathsf{speed = \frac{distance}{time} }}[/tex]

Our hunt for time — Speed in both the scenarios is known to us whereas the distance is same.

Sound

[tex] \mathsf{330 = \frac{d}{time_{s}} }[/tex]

[tex] \underline{\mathsf{time _{s} = \frac{d}{330} }}[/tex]

Light

[tex] \mathsf{3 \times {10}^{8} = \frac{d}{time _{l} } }[/tex]

[tex] \underline{ \mathsf{ time _{l} = \frac{d}{3 \times {10}^{8}} }}[/tex]

The best way of comparison is finding their ratio.

[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{ \frac{d}{330} }{ \frac{d}{3 \times {10}^{8} } } }[/tex]

simplifying the fraction

[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{d \times (3 \times {10}^{8} )}{330 \times d}}[/tex]

d gets canceled and we're left with the following expression

[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{ (3 \times10 \times {10}^{7} )}{330}}[/tex]

30, being a common factor in the numerator as well as denominator, gets canceled out. and in its place remains 1/ 11

(why?

=> 30÷330 = 1÷11)

[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{ 1\times {10}^{7} }{11}}[/tex]

taking timeₛ to the numerator on the other side.

[tex] \implies \mathsf{time_{s} = \frac{ 1\times {10}^{7} }{11}\times time_{l}}[/tex]

Therefore, we get timeₛ is approx. 10⁶ times the timeₗ.

That's a big difference, no wonder light's way much faster than sound.

As lesser the time taken to cover a distance, faster is the wave.

The sound takes about 874,000 times MORE time than the light takes.

An object following a straight-line path at constant speed is option C.) has zero acceleration.

There are no forces operating on a body if it is travelling straight ahead at a steady speed. There are no forces operating on a body if it is travelling straight ahead at a steady speed.

Note that the physics concept of acceleration measures how quickly an object's motion is changing. An object's speed or velocity is what largely defines its motion.

Therefore, An object is considered to be accelerating when its velocity changes over time and as such  since acceleration of the object is  said to be  zero, one can say that the net force acting on it is also zero.

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Answer:

1.24

Explanation:

The resistivity of copper[tex]\rho_1=2.65\times 10^{-8}\ \Omega-m[/tex]

The resistivity of Aluminum,[tex]\rho_2=1.72\times 10^{-8}\ \Omega-m[/tex]

The wires have same resistance per unit length.

The resistance of a wire is given by :

[tex]R=\rho \dfrac{l}{A}\\\\R=\rho \dfrac{l}{\pi (\dfrac{d}{2})^2}\\\\\dfrac{R}{l}=\rho \dfrac{1}{\pi (\dfrac{d}{2})^2}[/tex]

According to given condition,

[tex]\rho_1 \dfrac{1}{\pi (\dfrac{d_1}{2})^2}=\rho_2 \dfrac{1}{\pi (\dfrac{d_2}{2})^2}\\\\\rho_1 \dfrac{1}{{d_1}^2}=\rho_2 \dfrac{1}{{d_2}^2}\\\\(\dfrac{d_2}{d_1})^2=\dfrac{\rho_1}{\rho_2}\\\\\dfrac{d_2}{d_1}=\sqrt{\dfrac{\rho_1}{\rho_2}}\\\\\dfrac{d_2}{d_1}=\sqrt{\dfrac{2.65\times 10^{-8}}{1.72\times 10^{-8}}}\\\\=1.24[/tex]

So, the required ratio of the diameter of Aluminum to Copper wire is 1.24.

I assume the curve is flat and not banked. A car making a turn on the curve has 3 forces acting on it:

• its weight, mg, pulling it downward

• the normal force from contact with the road, n, pushing upward

• static friction, f = µn, directed toward the center of the curve (where µ is the coefficient of static friction)

By Newton's second law, the net forces on the car in either the vertical or horizontal directions are

∑ F (vertical) = n - mg = 0

∑ F (horizontal) = f = ma

where a is the car's centripetal acceleration, given by

a = v ²/r

and where v is the maximum speed you want to find and r = 25 m.

From the first equation, we have n = mg, and so f = µmg. Then in the second equation, we have

µmg = mv ²/r   ==>   v ² = µgr   ==>   v = √(µgr )

So the maximum speed at which the car can make the turn without sliding off the road is

v = √(0.80 (9.80 m/s²) (25 m)) = 14 m/s

Answer:

The answer is "0.82 c".

Explanation:

Given:

Spacecraft speed 1 is [tex]u = + 0.66 \ c[/tex]

Space velocity 2 relative to spacecraft 1 is [tex]v = + 0.34\ c[/tex]

The spacecraft velocity 2 measured by the Earth observation

   [tex]\to u' = \frac{u +v}{1 + ( \frac{uv}{c^2})}[/tex]

            [tex]= \frac{0.66 \ c +0.34\ c}{ 1+ (\frac{0.66\ c \times 0.33\ c }{c^2})}\\\\ = \frac{1 \ c }{ 1+ (\frac{0.2178\ c^2 }{c^2})}\\\\ = \frac{1 \ c }{ 1+ (0.2178 )}\\\\ = \frac{1 \ c }{ 1.2178 }\\\\=0.82\ c[/tex]

Answer:

C. Mass

Explanation:

Answer:

I am serious about that

Explanation:

.......

The frequency is 4,6E14 Hz.

What is the frequency?

Frequency is the fee at which modern changes direction in step with 2nd. it's far measured in hertz (Hz), a worldwide unit of degree wherein 1 hertz is identical to 1 cycle in line with 2d. Hertz (Hz) = One hertz is the same as 1 cycle in step with the second. Cycle = One entire wave of alternating present-day voltage.

Frequency describes the number of waves that pass a hard and fast place in a given quantity of time. So if the time it takes for a wave to skip is half of 2d, the frequency is 2 per 2nd. If it takes 1/one hundred of an hour, the frequency is a hundred in step with hour.

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Answer:

analyze, assess or interpret an historical event, era, or phenomenon,.

Explanation:

Secondary sources are works that analyze, assess or interpret an historical event, era, or phenomenon, generally utilizing primary sources to do so. Secondary sources often offer a review or a critique. Secondary sources can include books, journal articles, speeches, reviews, research reports, and more.

Answer:

V = V0 + a t

V = 75 - 9.8 * 3 = 45.6 m/s

The final velocity of the projectile after 3 seconds is equal to 45.6 m/s.

The equations of motion can be defined as the relation of the motion of a physical system as the function of time and set up the relationship between the displacement (s), acceleration, velocity (v & u), and time of a moving system.

Given, the initial velocity of the projectile, u = 75 m/s

The time taken by the projectile, t = 3 sec

The acceleration due to gravity upward, g = - 9.8 m/s²

From the first equation of motion we can calculate the final velocity of the projectile:

v = u + at

v = u - gt

v = 75 - 9.8 ×(3)

v = 75 - 29.4

v = 45.6 m/s

Therefore, the final velocity of the projectile after three seconds is 45.6 m/s.

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