A runner with a mass of 70 kg accelerates from 0 m/s to 8 m/s in 9 s. Find the magnitude of the net force (in newtons) on the runner using the alternate form of Newton's second law. Round your answer to the nearest whole number.

Answer

Answer:

a. a photon of energy 5 is absorbed

Explanation:

Because when an electron in a lower energy state absorbs energy, in form of photons it moves to higher energy stage in this case 5 photons because it moved from 5 to 10

Your question has been heard loud and clear

Torque = 6Nm

Angular acceleration= 7.5 revolutions / second

Moment of inertia = ?

Torque = Moment of inertia * Angular acceleration

Therefore , moment of intertia = Torque / Angular acceleration

Moment of inertia = 6 / 7.5 = 0.8 Kgm^2

Moment of inertia of wheel = 0.8 Kgm^2

Thankyou

Answer:

Area is a scalar quantity because there is no need of direction to define and also follow the algebraic summation. When we talk about vector there exists a frame of reference with a certain origin. It actually depends on the fact of the physical area, but if that factor changes to a non-directional object such as a rug spread on the floor, you can consider the area or a region as a scalar. (*Scalars are quantities that are fully described by a magnitude (or numerical value) alone.)

Hope this helps!

Although they're all 'close', none of the planets orbits in the same plane as any other planet.  They're all in slightly different planes.

The farthest out compared to all the others is Pluto, with an orbit inclined about 17 degrees compared to the ecliptic plane (Earth's orbit).  But Pluto is officially not a planet, so I don't think it's a good answer.

The next greatest inclination compared to Earth's orbit is Mercury.  That one is about 7 degrees.

The other six planets are all in different orbital planes inclined less than 7 degrees compared to Earth's orbit.

Answer:

D = 4.47d

Explanation:

given that

1/R(eq) = 20/R

R(eq) = R/20

also, we know that the formula for resistance is given by the relation

R = pl/A, where A is πd²/4

If we substitute the value of A, we have

R = pl/(πd²/4)

R = 4pl/πd²

Now, we substitute this in the earlier derived equation

R(eq) = (4pl/πd²) / 20

R(eq) = pl/5πd²

To find the resistance of a single wire made of the same material, the resistance is

R(D) = 4pl / πD²

R(eq) = R(D), and thus

pl/5πd² = 4pl/πD²

1/5d² = 4/D²

D² = 20d²

D = √20d²

D = 4.47 d

Answer:

Explanation:

Given,

F = 100 , M = 25

Now, let's find the value of A

[tex] \sf{F = MA}[/tex]

plug the values

⇒[tex] \sf{100 = 25 A}[/tex]

Swap the sides of the equation

⇒[tex] \sf{25A = 100}[/tex]

Divide both sides of the equation by 25

⇒[tex] \sf{ \frac{25A}{25} = \frac{100}{25} }[/tex]

Calculate

⇒[tex] \sf{A = 4}[/tex]

Hope I helped!

Best regards!!

Given:-

To find out:-

Calculate the acceleration, a ?

Formula applied:-

F = m × a

Solution:-

We know,

[tex] \sf{F = m × a}[/tex]

Substituting the values of mass and acceleration,we get

[tex] \sf\implies \: 100 = 25 \times a[/tex]

[tex] \sf \implies a = \cancel \dfrac{100}{25} [/tex]

[tex] \sf \implies a = 4 \: ms {}^{ - 1} [/tex]

Mass of fish is 5.09Kg

Explanation:

First to find the spring constant K using

k = F/s

= 220/0.15 = 1466.7 N/m

So using the formula

T = 2π√(m/k)

f = 1/T = 1/2πx √(k/m)

f² x 4π²= k/m

So

m = k/(f² x π²)

m = 1466.7/(2.7² x 4π²)

m = 5.09 kg

Answer:

89.6 cm

Explanation:

From the question,

Volume of the rectangular object = Mass/Density.

V = m/D.................. Equation 1

Given: m = 1.278 kg, D = 4.98 g/cm³ = 4980 kg/m³

Substitute into equation 1

V = 1.278/4980

V = 2.57×10⁻⁴ m³.

But,

V = lwh............... Equation 2

Where l = length of the rectangular object, w = width of the rectangular object, h = height of the rectangular object.

make h the subject of the equation

h = V/lw........... Equation 3

Given: V = 2.57×10⁻⁴ m³, l = 0.047 m, w = 0.061 m.

Substitute into equation 3

h = 2.57×10⁻⁴/(0.047×0.061)

h = 0.896 m

h = 89.6 cm

A father and his son want to play on a seesaw. Due to his larger size than that of the son, the father should outweigh the boy on the opposing sides.

A seesaw is a long, narrow board with a single pivot point, which is often situated in the middle of both ends. As one end rises, the other falls.

Rugby continues to have far more health advantages than hazards.

A father and his son want to play on a seesaw. Due to his larger size than that of the son, the father should outweigh the boy on the opposing sides.

To know more about seesaw and outweigh

https://brainly.com/question/27823383

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Answer: 90 m/s

Explanation:

The formula for speed is distance/time. The distance is 180 m and the time it took for the ball to travel is 2 s.

180 m/2 s = 90 m/s

Answer:

A) -40° C and -40° F

B) 574.25° K and 574.25° F

Explanation:

see attachment for calculation and explanation

Answer:

(a) -136.8 Ns.

(b) -1.135 N

Explanation:

(a)

Impulse: This can be defined as the change in momentum.

From the question,

I = mv-mu.................. Equation 1

Where I = impulse, m = mass of the hammer, v = final velocity, u = initial velocity.

Given: m = 18 kg, u = 7.6 m/s, v = 0 m/s (to rest)

Substitute these values into equation 1

I = 18(0)-18(7.6)

I = -136.8 Ns.

(b)

Average force = It.............. Equation 2

Where t = time.

Given: t = 8.3 ms = 0.0083 s.

Average force = -136.8(0.0083)

Average force = -1.135 N

Answer:

Option (A) : Zero

Explanation:

Electric field Intensity inside a metallic body is always ZERO.

Answer:

The  ratio is  [tex]\frac{w_1}{w_2} = \frac{R_2}{R_1}[/tex]

Explanation:

From the question we are told that

   The first radius is [tex]R_1[/tex]

    The  second radius is  [tex]R_2[/tex]

Generally the angular speed of the turntable is mathematically represented as

       [tex]w_1 = \frac{ v_k }{R_1 }[/tex]

Generally the angular speed of the rubber roller is mathematically represented as

        [tex]w_2 = \frac{ v_k }{R_2 }[/tex]

Where [tex]v_k[/tex] is the velocity of both turntable and  rubber roller

So

    [tex]\frac{w_1}{w_2} = \frac{\frac{v_k}{R_1} }{\frac{v_k}{R_2} }[/tex]

    [tex]\frac{w_1}{w_2} = \frac{R_2}{R_1}[/tex]

Answer:

2 oxygen 1 carbon

Explanation:

Answer:

2 oxygen, 1 carbon

Explanation:

Answer:

10⁻¹² W / m²

Explanation:

The feeble sound that a man can hear is of the vale which measures 0 on decibel scale . The intensity of sound in terms of J / m² .s is 10⁻¹² W / m² .

So the intensity of sound of monkey at 2.5 km must be 10⁻¹² W / m² .

Answer and Explanation: Centripetal Acceleration is the change in velocity caused by a circular motion. It is calculated as:

[tex]a_{c}=\frac{v^{2}}{r}[/tex]

v is linear speed

r is radius of the curve the object in traveling along

For its first lap:

[tex]a_{c}_{1}=\frac{v_{i}^{2}}{R}[/tex]

After a while:

[tex]a_{c}_{2}=\frac{(4v_{i})^{2}}{R}[/tex]

[tex]a_{c}_{2}=\frac{16v_{i}^{2}}{R}[/tex]

Comparing accelerations:

[tex]\frac{a_{c}_{2}}{a_{c}_{1}}=\frac{16.v_{i}^{2}}{R}.\frac{R}{v_{i}^{2}}[/tex]

[tex]\frac{a_{c}_{2}}{a_{c}_{1}}=\frac{16.v_{i}^{2}}{R}.\frac{R}{v_{i}^{2}}[/tex]

[tex]\frac{a_{c}_{2}}{a_{c}_{1}}=16[/tex]

[tex]a_{c}_{2}=16a_{c}_{1}[/tex]

With linear speed 4 times faster, centripetal acceleration is 16 times greater.

Answer:

V_ind = 4 × 10^(-4) V

Explanation:

We are given;

Magnetic field; B = 80 μT = 8 × 10^(-5) T

Angle;θ = 30°

Lenght;L = 50 cm = 0.5 m

Speed; v = 20 m/s

Now, formula for the induced potential difference is known as;

V_ind = NBLVsin θ

Where;

V_Ind = Induced potential difference/voltage

N = Number of turns

B = Magnetic field

V = velocity

L = length

Number of turns in this case is 1 since it's just a wire between both ends.

Thus, plugging in the relevant values, we have;

V_ind = 1 × 8 × 10^(-5) × 20 × 0.5 × sin 30

V_ind = 4 × 10^(-4) V

Answer:

A) Change in potential energy is approximately 766 KJ

B) The minimum work required by the hiker is 765 KJ

C). Yes, the actual work can be greater than this

Explanation:

A) The hiker's potential energy can be calculated at the two different elevations, and then subtracted.

P.E at 1280 m = m X g X h = 60.5kg X 9.81 m/s2 X 1280 = 759, 686 J

P.E at 2570 m = m X g X h = 60.5kg X 9.81 m/s2 X 2570 = 1, 525, 307.85 J

Change in P.E = 1, 525, 307.85 J -759, 686 J = 765, 621.85 J = 766 KJ

B) Work which was done = Force X distance moved.

The force can be got from the effect of gravity on the hiker's mass = 60.5 kg X 9.81 = 593.5 Newton.

The distance moved can be obtained by subtracting the two elevations = 2570 -1280 = 1290 m

Work done = 593 X 1290 = 765, 615 J

The minimum work required by the hiker is 765 KJ

C) Yes, the actual work can be greater than this. This is because we can now put into consideration the fact that the hiker is climbing up the elevation against the force of gravity. This will mean that the hiker is actually doing more work than if he covered the distance on flat terrain,

Answer:

a). C = b/2   and C = b/4

b).  [tex]$ \therefore T = 2 \pi \sqrt{\frac{m_1 +m_2}{k (m_1 + m_2)}} = 2 \pi \sqrt{ \mu/k}$[/tex]

c). m = 63.4 kg (approx.)

Explanation:

Ex. 2.4.4

The total force acting on mass m is [tex]$ F = F_{spring }= -kx $[/tex] , where x is the displacement from the equilibrium position.

The equation of motion is [tex]$ m {\overset{..}x} + kx = 0 $[/tex]

or [tex]$ {\overset{..}x}+ \frac{k}{m}x=0 $[/tex]     or   [tex]$ {\overset{..}x} + w_0^2 x = 0 $[/tex] ,    where [tex]$ w_0 = \sqrt{\frac{k}{m}} $[/tex]  

The solution is [tex]$ x = A \cos (w_0t + \phi) $[/tex] ,  where A and Ф are constants.

A is amplitude of  motion

[tex]$ w_0$[/tex] is the angular frequency of motion

Ф is the phase angle.

Now, [tex]$ w_0 = 2 \pi f_0 = \sqrt{k/m} $[/tex]

or [tex]$ m = \frac{k}{4\pi f_0^2} $[/tex]

Given [tex]$ f_0 = 0.8 Hz , k = 4 N/m $[/tex]

a).  [tex]$ m = \frac{4}{4(3.14)^2(0.8)^2} = 0.158\ kg$[/tex]

b). [tex]$ w_0^2 = k/m $[/tex]  

or  [tex]$ m = k/ w_0^2 = k / (2\pi f_0)^2 = k / 4 \pi^2 f_0^2 $[/tex]

Ex. 2.4.5

a). Total force acting on the mass m is [tex]$F = F_{spring}+f $[/tex]

                                                                    [tex]$ = -kx-bv $[/tex]

    The equation of motion is [tex]$ m {\overset{..}x}= -kx-b{\overset{.}x} $[/tex]

    or [tex]$ w_0 = \sqrt{\frac{k}{m}} $[/tex] ,  angular frequency of the undamped oscillation.

   γ = b/2m  is called the damping coefficient (γ=C)

   [tex]$ k = m w_0^2 = 4 \pi^2 m f_0^2 $[/tex]

   for 1 kg weight (= 9.8 N), [tex]$ f_0$[/tex] = 1.1 Hz

    k = 4 x (3.14)² x (9.8) x 1.1²  = 4.6 x 10² N/m

  For 2 kg weight (= 19.6 N), [tex]$ f_0$[/tex] = 0.8 Hz

    k = 4 x 9.8596 x 2 x 9.8 x 0.8²  = 5 x [tex]$ 10^7$[/tex] N/m

   [tex]$ \gamma = \frac{b}{2m_1} = \frac{b}{2m_2} $[/tex]

or [tex]$ \gamma = \frac{b}{2 \times 1} = \frac{b}{2 \times 2} $[/tex]

γ = b/2 (for 1 kg)  and   γ = b/4 (for 2 kg)

C = b/2   and C = b/4

b). [tex]$ w_0^2 = \frac{k}{m} \Rightarrow \frac{k}{w_0^2} = \frac{k}{(2 \pi f_0)^2} = \frac{k}{4 \pi^2 f_0^2} $[/tex]

 For two particle problem,

   [tex]$ w'_0^2 = \sqrt{\frac{k(m_1+m_2)}{m_1 +m_2}} $[/tex]

[tex]$ \therefore T = 2 \pi \sqrt{\frac{m_1 +m_2}{k (m_1 + m_2)}} = 2 \pi \sqrt{ \mu/k}$[/tex]

where, μ is the reduced mass.

This time period is same for both the particles.

c). [tex]$ m =\frac{k}{4 \pi^2 f_0^2}$[/tex]

        [tex]$ = \frac{5 \times 10^2}{4 \times 9.14^2 \times 0.2} = 63.4\ kg $[/tex]  ( approx.)

Answer:

La resistencia que debe ser conectada en paralelo con una de 20 Ω para hacer una  resistencia combinada de 15 Ω tiene un valor de 60 Ω

Explanation:

Las resistencias son aquellos dispositivos en los circuitos eléctricos que suelen emplearse para oponerse al paso de la corriente eléctrica.

Se denomina resistencia resultante o equivalente al valor de la resistencia que se obtiene al considerar un conjunto de ellas.

Cuando tenes resistencias en paralelo la corriente se divide y circula por varios caminos.

La resistencia equivalente de un circuito de resistencias en paralelo es igual al recíproco de la suma de los inversos de las resistencias individuales:

[tex]R=\frac{1}{\frac{1}{R_{1} } +\frac{1}{R_{2} } +...+\frac{1}{R_{N} }}[/tex]

Esto también puede ser expresado como:

[tex]\frac{1}{R} =\frac{1}{R_{1} } +\frac{1}{R_{2} } +...+\frac{1}{R_{N} }[/tex]

Entonces, en este caso sabes:

Reemplazando:

[tex]\frac{1}{15} =\frac{1}{20}+\frac{1}{R2}[/tex]

y resolviendo:

[tex]\frac{1}{R2} =\frac{1}{15} -\frac{1}{20}[/tex]

[tex]\frac{1}{R2} =\frac{1}{60}[/tex]

se obtiene:

R2=60 Ω

La resistencia que debe ser conectada en paralelo con una de 20 Ω para hacer una  resistencia combinada de 15 Ω tiene un valor de 60 Ω

Using

V = Amplitude x angular frequency(omega)

But omega= 2πf

= 2πx875

=5498.5rad/s

So v= 1.25mm x 5498.5

= 6.82m/s

B. .Acceleration is omega² x radius= 104ms²

Answer:

a

  [tex]v _{max } = 6.82 \ m/s[/tex]

b

 [tex]a_{max} = 37489.5 \ m/s^2[/tex]

Explanation:

From the question we are told that

   The amplitude is [tex]A = 1.24 \ mm = 1.24 * 10^{-3} \ m[/tex]

   The frequency is  [tex]f = 875 \ Hz[/tex]

Generally the maximum speed is mathematically represented as

           [tex]v _{max } = A * 2 * \pi * f[/tex]

=>        [tex]v _{max } = 1.24*10^{-3} * 2 * 3.142 * 875[/tex]

=>        [tex]v _{max } = 6.82 \ m/s[/tex]

Generally the maximum acceleration is mathematically represented as

       [tex]a_{max} = A * (2 * \pi * f)[/tex]

=>      [tex]a_{max} = 1.24*10^{-3} * (2 * 3.142 * 875 )^2[/tex]

=>       [tex]a_{max} = 37489.5 \ m/s^2[/tex]

Answer:

C. All waves have the same speed.

Explanation:

Wave equation is given as;

V = fλ

where;

V is the speed of the wave

f is the frequency of the wave

λ is the wavelength

The speed of the wave depends on both wavelength and frequency

The speed of the electromagnetic waves in a vacuum is 3 x 10⁸ m/s, this also the speed of light which is constant for all electromagnetic waves.

Therefore, the correct option is "C"

C. All waves have the same speed.

Complete Question

 An object floats in water with 5/8 of its volume submerged. The ratio of the density of the object to that of water is:

(a) 8/5

(b) 1/2

(c) 3/8

(d) 5/8

(e) 2/1

Answer:

  The correct option is  d

Explanation:

 From the question we are told that

     The ratio of the  volume of the object submerged to the total volume of the object  is  [tex]\frac{V_w}{V_o} = \frac{5}{8}[/tex]

Generally the buoyancy force acting on the object is equal to the weight of the water displaced and this is mathematically represented as

      [tex]F_b = W[/tex]

Now the mass of the water displaced is mathematically represented as

      [tex]m_w = \rho_w * V_w[/tex]

While the mass of the object is mathematically represented as

    [tex]m_o = \rho_o * V_o[/tex]

So  

      [tex]F_b = W \ \equiv \ \rho * V_o * g = \rho * V_w * g[/tex]

   =>    [tex]\frac{V_w}{V_o} = \frac{\rho_o}{\rho_w}[/tex]

From the question that it volume of the water displace (equivalent to the volume of the object in water  ) to the volume of the total object is

        [tex]\frac{V_w}{V_o} = \frac{5}{8}[/tex]

So

     [tex]\frac{\rho_o}{\rho_w} = \frac{5}{8}[/tex]

Answer:

The pressure is  [tex]P_2 = 4.25 \ a.t.m[/tex]

Explanation:

From the question we are told that

   The initial pressure is [tex]P_1 = 11.2\ a.t.m[/tex]

   The  temperature is  [tex]T_1 = 299 \ K[/tex]

Let the first volume be  [tex]V_1[/tex] Then the final volume will be  [tex]2 V_1[/tex]

 Generally for a diatomic  gas

           [tex]P_1 V_1 ^r = P_2 V_2 ^r[/tex]

Here r is the radius of the molecules which is  mathematically represented as

    [tex]r = \frac{C_p}{C_v}[/tex]

Where [tex]C_p \ and\ C_v[/tex] are the molar specific heat of a gas at constant pressure and  the molar specific heat of a gas at constant volume with values

     [tex]C_p=7 \ and\ C_v=5[/tex]

=>   [tex]r = \frac{7}{5}[/tex]

=>  [tex]11.2*( V_1 ^{\frac{7}{5} } ) = P_2 * (2 V_1 ^{\frac{7}{5} } )[/tex]

=>   [tex]P_2 = [\frac{1}{2} ]^{\frac{7}{5} } * 11.2[/tex]

=>  [tex]P_2 = 4.25 \ a.t.m[/tex]

The final pressure of the gas will be 4.244 atm.

Given information:

The initial pressure of the gas is [tex]P_1=11.2\rm\;atm[/tex].

The initial temperature of the gas is [tex]T_1=299\rm\; K[/tex].

Let the initial volume of the gas be V. So, the final volume will be double or 2V.

The given diatomic gas is expanded adiabatically. So, the equation of the adiabatic process will be,

[tex]P_1V_1^{\gamma}=P_2V_2^{\gamma}[/tex]

where [tex]\gamma[/tex] is the ratio of specific heats of the gas which is equal to 1.4 for a diatomic gas.

So, the final pressure [tex]P_2[/tex] can be calculated as,

[tex]P_1V_1^{\gamma}=P_2V_2^{\gamma}\\11.2\times V^{1.4}=P_2\times (2V)^{1.4}\\P_2=4.244\rm\;atm[/tex]

Therefore, the final pressure of the gas will be 4.244 atm.

For more details, refer to the link:

https://brainly.com/question/16014998

Answer:

The  minimum thickness is [tex]t = 1.0192 *10^{-7} \ m[/tex]    

Explanation:

From the question we are told that

   The  refractive index is  [tex]n = 1.29[/tex]

    The  wavelength of the light is  [tex]\lambda = 636 \ nm = 636 *10^{-9} \ m[/tex]

    The  refractive index of the glass lens is  [tex]n_g = 1.56[/tex]

Generally the condition for destructive interference of a films is  

               [tex]2t = [ m + \frac{1}{2} ] \frac{\lambda}{n}[/tex]

for  minimum m =  0  

       [tex]2t = [ 0 + \frac{1}{2} ] \frac{\lambda}{n}[/tex]

=>    [tex]2t = [ 0 + \frac{1}{2} ] \frac{636 *10^{-9}}{1.56}[/tex]

=>  [tex]t = 1.0192 *10^{-7} \ m[/tex]    

Answer:

E. The ocean gains more entropy than the iron loses.

Explanation:

When there is a spontaneous process , entropy of the system increases . Here hot iron is losing entropy and ocean is gaining entropy . Net effect will be gain of entropy . That means entropy gained by ocean is more than entropy lost by iron .

Hence option E is correct .

Answer:

7 degree

Explanation:

given data

width = 4.1 inches

length = 35.4 inches

solution

we consider as per fig

O is mid point of BC

so  OB  = 2.05 inches

and

AB = [tex]\sqrt{OB^2 + OA^2}[/tex]

AB = [tex]\sqrt{2.05^2 + 35.4^2}[/tex]

AB = 35.078 inches

so

[tex]sin \frac{\alpha }{2} = \frac{OB}{AB}[/tex]

[tex]sin \frac{\alpha }{2} = \frac{2.05}{35.078}[/tex]

[tex]\alpha = 7 degree[/tex]

1/200 that should get your

answer