a boy standing by a lake sees a fish in the pond and tries to thrust a spear into it he will success or not​ explain with reason​

Answer:

c < a<=b

Explanation:

Tensile stress = (force) /Area

for A:

Tensile stress = 200/1 =200N/mm²

For B:

Tensile stress = 200/1 =200N/mm2

For C:

Tensile stress = 100/2 =50N/mm²

Ranking from smallest to largest we have;

C<A<=B which is option 4

Answer:

correct tysmm

Explanation:

Answer:

0.518 m/s

Explanation:

To solve this question, we would use the Law of conservation of momentum.

It is stated that the skateboard and the person were at rest initially, this means that their initial momentum is 0. Since they aren't moving.

And from the law if conservation of momentum, we know that initial momentum must be equal to final momentum.

The final momentum of the bricks will be 2* 0.9 * 19 = 34.2 kg m/s.

This means that the momentum of the person and that of the skateboard has to be 34.2 kg m/s also, although, it will be in the opposite direction.

Mass of the person plus that of the skateboard is

64 + 2 = 66 kg,

If we divide the momentum of the person and that of the skateboard by the mass of the both of them, we get the speed at which they are moving after the bricks are thrown

Recoil speed = (34.2 kg m/s)/(66 kg) = 0.518 m/s.

The recoil speed of the person is 0.518 m/s

As per the conservation of momentum, the initial momentum should be equivalent to the final momentum

So, here the final momentum should be

=  2* 0.9 * 19

= 34.2 kg m/s.

Now the mass of the person should be

= 64 + 2

= 66 kg,

Now the recoil speed should be

Recoil speed = (34.2 kg m/s)/(66 kg)

= 0.518 m/s.

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Answer:

D. The object moves away from the origin at a speed of 3 m/s, stands still 6 m away from the origin for 3 seconds, then moves toward the origin at a speed of 2 m/s.

Explanation:

I just got it right lol

Answer: 0.43 m

Explanation:

Given

mass of bullet [tex]m=10\ gm\approx 0.01\ kg[/tex]

mass of block [tex]M=1.95\ kg[/tex]

The Force constant of spring is [tex]k=23.9\ N/m[/tex]

Speed of bullet is [tex]u=300\ m/s[/tex]

Conserving the energy i.e. kinetic energy of the bullet and box is converted into Elastic potential energy of spring

[tex]\Rightarrow \dfrac{1}{2}(M+m)v^2=\dfrac{1}{2}kx^2[/tex]

Conserving linear momentum

[tex]\Rightarrow mu=(M+m)v\\\\\Rightarrow v=\dfrac{mu}{M+m}[/tex]

Put the value of [tex]v[/tex] we get

[tex]\Rightarrow x=mu\sqrt{\dfrac{1}{k(M+m)}}\\\Rightarrow x=0.01\times 300\sqrt{\dfrac{1}{23.9(0.01+1.95)}}\\\Rightarrow x=3\sqrt{\dfrac{1}{46.844}}=\dfrac{3}{6.844}=0.43\ m[/tex]

Thus, spring will be compressed to a distance of [tex]0.43\ m[/tex]

Answer:

the oscillations of the electrons must be in the 10⁸ Hz = 100 MHz range

Explanation:

The speed of a wave of radio, television, light, heat, all are manifestations of electromagnetic waves that are oscillations of electric and magnetic fields that support each other, the speed of all these waves is the same and the vacuum is equal to c = 3 108 m / s

All waves have a relationship between the speed of the wave, its frequency and wavelength

          c = λ f

          f = c /λ

for this case lam = 1 m

          f = 3 10⁸/1

          f = 3 10⁸ Hz

the oscillations of the electrons must be in the MHz range

It should be clarified that the speed of light in air is a little lower

          n = c / v

          v = c / n

the refractive index of vacuum is n = 1 and the refractive index of air is n = 1.000002

Answer:

The correct answer is A) It is upright and 1.5m behind the mirror

Explanation:

Your reflection must be upright, meaning vertical/erect, and the distance will be the exact same. Also, the reflected ray appears as if it had traveled from an object located behind the mirror.

Answer:

C. Sigmund Freud . . . Carl Jung

Explanation:

edge 2021

C.Sigmund Freud and Carl Jung both heavily relied on dream analysis in their treatment of patients.

Freud is well-known for inventing and developing the approach of psychoanalysis; for articulating the psychoanalytic idea of motivation, intellectual infection, and the structure of the unconscious; and for influencing medical and popular conceptions of human nature by using positing both everyday and strange thought.

Sigmund Freud was an Austrian neurologist who's perhaps maximum known as the founding father of psychoanalysis. Freud advanced a fixed of therapeutic strategies centered on communication therapy that worried the use of techniques that include transference, loose affiliation, and dream interpretation.

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Answer:

e. the number of active motor units increases.

Explanation:

There is a direct relationship between the number of active motor units and the grip strength in a given scenario. For example, increase in the grip strength leads to increase in the number of active motor units. In the other-hand, the decrease in grip strength leads to the decrease in the number of active motor units.

Answer:

During the northern hemisphere winter solstice, the Sun's incoming rays are perpendicular to the Tropic of Capricorn at 23.5 degrees south latitude.

Explanation:

Spring begins

While the Earth is revolving around the sun, less direct sunlight is reaching the Northern Hemisphere than the Southern Hemispherethebn there would be a summer season in the northern hemisphere.

It is a system that collection of all the planets and spatial bodies revolving around the sun because of the gravitational pull of the sun.

Our Solar System is based on a heliocentric model in which the Sun is assumed to reside at the central point of the planetary system.

While the Earth revolves around the sun, the Northern Hemisphere receives less direct sunlight than the Southern Hemisphere. If this were not the case, the Northern Hemisphere would experience summer.

Thus, the correct answer is option A.

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Answer:

the motorcycle travels 522 miles in 18 seconds Explanation: 29 x 18 is 522 I'm pretty sure that's what it was asking but I don't know

Answer:

Following are the solution to the given question:

Explanation:

The input linear polarisation was shown at an angle of [tex]2 \mu[/tex]. It's a very popular use of a half-wave plate. In particular, consider the case [tex]\mu = 45 \pm[/tex], at which the angle of rotation is [tex]90\pm[/tex]. HWP thereby provides a great way to turn, for instance, a linear polarised light that swings horizontally to polarise vertically. Illustration of action on event circularly polarized light of the half-wave platform. Customarily it is the slow axis of HWP that corresponds to either the rotation. Note that perhaps the vector of polarization is "double-headed," i.e., the electromagnetic current swinging back and forward in time. Therefore the turning angle could be referred to as the rapid axis to reach the same result. Please find the attached file.

Answer:

momentum=mass x velocity= 10 x 2 = 20kgm/s

Answer:

Magnetic poles

Explanation:

Magnetic poles are the regions where the magnet's force is strongest, one is the north pole and one is the south pole.

Answer:

its B

Explanation:

Answer:

533.33 nm

Explanation:

Since dsinθ = mλ  for each slit, where m = order of slit and λ = wavelength of light. Let m' = 10 th order fringe of the first slit of wavelength of light, λ = 640 nm and m"= 12 th order fringe of the second slight of wavelength of light, λ'.

Since the fringes coincide,

m'λ = m"λ'

λ' = m'λ/m"

= 10 × 640 nm/12

= 6400 nm/12

= 533.33 nm

Answer:

the answer is c, 3m......

When a train is moving at the speed of 30 m/s. The wavelength of the wave is 3 m.

Wavelength is the characteristic of the wave which represents the distance between the adjacent crest or trough of the wave.

Given is the speed of the train of waves 30 m/s and frequency of the wave is 10 Hz, then the wavelength is related to speed and wavelength as

v = fλ

30 = 10 × λ

λ = 3 m

Thus, the wavelength of the wave is 3 m.

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Answer:

35 N

Explanation:

F = ma

centripetal force = 10(3.5) = 35 N

Answer:

D

Explanation:

Answer:

average speed of the fist during the hook = 15 m/s or 1500 cm/s

Explanation:

We are given;

Speed of shoulder contraction, v_s = 75 cm/s = 0.75 m/s

Distance moved through the arc length by shoulder, d_s = 5 cm = 0.05 m

Distance moved by the fist, d_f = 100 cm = 1 m

Now, we are to find the average speed of the fist during the hook; v_f

Thus can be gotten from proportion;.

d_f/d_s = v_f/ v_s

Making V_f the subject, we have;

v_f = (d_f × v_s)/d_s

Thus;

v_f = (1 × 0.75)/0.05

v_f = 0.75/0.05

v_f = 15 m/s

Answer:

It's plastic.

trust me it's plastic, i've rad it somewhere.

All of them have something that's not like the others.

-- Rubber is the only one on the list that has two repeated letters.

-- Plastic is the only one on the list thagt has no repeated letters.

-- Plastic is the only one on the list that has no 'r' in its name.

-- Copper is the only one on the list that is an element, not a compound.

-- Copper is the only good electrical conductor on the list.

-- Plastic is the only one on the list with more than six letters in its name.

-- Rubber is the only one on the list with no 'p' in its name.

-- Plastic is the only one on the list that doesn't end in "-er".

Answer:

1)   x = x₀ + vot - ½ c t² - 1/6 bt³,    v = v₀ - ct - ½ b t²

2)   v₁ = 5.25 m/s,         v₂ = -8 m/s

Explanation:

1) For this exercise, the relationship of the body is not constant, so you must use the definition of speed and position to find them.

acceleration is

           a = c + bt

a) the relationship between velocity and acceleration

           a = [tex]\frac{dv}{dt}[/tex]

           dv = -a dt

The negative sign is because the acceleration is contrary to the speed to stop the vehicle.

we integrate

           ∫ dv = - ∫ a dt

           ∫ dv = -∫ (c + bt) dt

            v = -c t - ½ b t²

This must be valued from the lower limit, the velocity is vo, up to the upper limit, the velocity is v for time t

             v - v₀ = -c (t-0) - ½ b (t²-0)

             v = v₀ - ct - ½ b t²

b) the velocity of the body is

             v = [tex]\frac{dx}{dt}[/tex]

             dx = v dt

we replace and integrate

              ∫ dx = ∫ (v₀ - c t - ½ bt²) dt

              x-x₀ = v₀ t - ½ c t² - ½ b ⅓ t³

Evaluations from the lower limit the body is at x₀ for t = 0 and the upper limit the body is x = x for t = t

           x - x₀ = v₀ (t-0) - ½ c (t²-0) + [tex]\frac{1}{6}[/tex]  (t³ -0)

           x = x₀ + vot - ½ c t² - 1/6 bt³

2) The speed when you reach the traffic light

Let's write the data that indicates, the initial velocity is vo = 15 m / s, the initial position is xo = 315m, let's use the initial values ​​to find the constants.

       t = 25 s x = 20

we substitute

          20 = 315 + 15 25 - ½ c 25² - 1/6 b 25³

         0 = 295 + 375 - 312.5 c - 2604.16 b

         670 = 312.5 c + 2604.16 b

we simplify

         2.144 = c + 8.33 b

Now let's use the equation for velocity,

        v = v₀ - ct - ½ b t²

        v = 15 - c 25 - ½ b 25²

        v = 15 - 25 c - 312.5 b

let's write our two equations

        2.144 = c + 8.33 b

        v = 15 - 25 c - 312.5 b

Let's examine our equations, we have two equations and three unknowns (b, c, v) for which the system cannot be solved without another equation, in the statement it is not clear, but the most common condition is that if the semaphore does not change, it follows with this acceleration (constant) to a stop

               a = c + b 25

from the first equation

              c = 8.33 / 2.144 b

              C = 3.885 b

we substitute in the other two

            v = 15 - 25 (3.885 b) - 312.5 b

            v = 15 - 409.6 b

final acelearation

            a = 28.885 b

let's use the cinematic equation

               [tex]v_{f}^2[/tex]= v² - 2 a x

                0 = v² - 2a 20

               0 = v² - (28.885b) 40

               v² = 1155.4 b

we write the system of equations

               v = 15 - 409.6 b

               v² = 1155.4 b

resolve

              v²= 1155.4 ( [tex]\frac{15 -v }{409.6}[/tex] )

              v² = 2.8 ( 15 -v)

              v² + 2.8 v - 42.3 = 0

              v=  [ -2.8 ±[tex]\sqrt {2.8^2 + 4 \ 42.3) }[/tex] ]/2 = [-2.8 ± 13.3]/2

              v₁ = 5.25 m/s

              v₂ = -8 m/s

Answer:

Pressure is the perpendicular force applied per unit area.

Answer:

B It is always increasing.

Explanation:

In Physics, entropy can be defined as the tendency or ability of a substance to reach maximum disorder i.e to be randomly distributed.

This ultimately implies that, entropy is a thermodynamic quantity that measures the degree of maximum disorder or randomness of a system.

The S.I unit used for the measurement of the degree of maximum order or randomness of a system is Joules per Kelvin (JK¯¹). An example of entropy is the mixing of ideal gases.

Generally, the entropy in an irreversible process always increases and as such the change in entropy has a positive value.

Hence, the entropy of the universe is always increasing because its energy flow is considered to be in a downward direction rather than upward i.e from a hot region to a cold region; making the energy to be evenly distributed.

Answer:

20 J/s

Explanation:

Given data

Kinetic energy=100 J

Time= 5 seconds

Hence the rate at which the kinetic friction work is

=100/5

=20 J/s

Therefore the answer is 20 J/s

The framers wanted senators to be more mature and more experienced than representatives. (C)

Answer:

C -> The framers wanted senators to be more mature and more experienced than representatives.