What frequency is received by a person watching an oncoming ambulance moving at 115 km/h and emitting a steady 753 Hz sound from its siren

Answer:

54 s

Explanation:

Given that,

Mass of a car, m = 15000 kg

Initial speed, u = 5.4 m/s

Final speed, v = 0 (it comes to rest)

Force, F = 1500 N

We need to find time when it comes to rest. Let it is t. Net force is given by :

F = ma, a is acceleration of the car

[tex]F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{15000\times (0-5.4)}{1500}\\\\t=54\ s[/tex]

So, it will take 54 seconds to come to rest.

The time required to bring the car to rest is 54 s and the right option is (b) 54 s.

To calculate the time required for the force to bring the car to rest, we use the formula below.

Formula:

Where:

Make t the subject of the equation

From the question,

Given:

Substitute these values into equation 2

Hence, The time required to bring the car to rest is 54 s and the right option is (b) 54 s.

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Answer:

D

Explanation:

5+25=30

Answer:

9 kg

Explanation:

Force= Mass * Acceleration

18 N= Mass * 2 m/s^2

(18 N / 2 m/s^2) = Mass

Mass= 9 kg

Answer:

ΔE = GmM/3R

Explanation:

The absolute potential energy of an object in a planet's field is given as:

E = -GmM/2r

where,

E = Potential Energy

G = Universal Gravitational Constant

m = mass of spaceship

M = Mass of Planet

r = distance from surface of planet

Therefore, for initial state:

E = E₁ and r = R

E₁ = - GmM/2R

and for final state:

E = E₂ and r = 3R

E₂ = - GmM/6R

So, the required energy will be:

ΔE = E₂ - E₁ = - GmM/6R + GmM/2R

ΔE = GmM(- 1/6R + 1/2R)

ΔE = GmM/3R

Answer:10.m and 10. M

Explanation:

A displacement vector with a magnitude of 20. m could have perpendicular components with magnitudes of C. 12 m and 16 m.

A displacement vector with a magnitude of 20. meters can be decomposed in 2 perpendicular components.

They would form a right triangle, in which the displacement vector would be the hypotenuse (a) and the components would be the legs (b, c).

Given the magnitude of the legs, we can calculate the magnitude of the hypotenuse using the Pythagorean theorem.

[tex]c = \sqrt{a^{2} + b^{2} }[/tex]

Let's use this formula to calculate the displacement vector for each pair of legs.

[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(10.m)^{2} + (10.m)^{2} }= 14.1m[/tex]

[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(12m)^{2} + (8.0m)^{2} }= 14.4m[/tex]

[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(12m)^{2} + (16m)^{2} }= 20m[/tex]

[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(16m)^{2} + (8.0m)^{2} }= 17.9m[/tex]

A displacement vector with a magnitude of 20. m could have perpendicular components with magnitudes of C. 12 m and 16 m.

Learn more: https://brainly.com/question/16426393

Explanation:

One common property with all halogens in group 7 is that they are all non-metals.

Fluorine, chlorine, Bromine and Iodine are classified as non-metallic elements and they have a high electronegativity.

The most prominent observation from halogens is that they all non-metallic in nature.

Answer:

meteoroids

Explanation:

when an asteroid (or really anything else) falls to earth, it is called a meteoroid

Answer:

Explanation:

The giant star must have at least once been the more massive star and then subsequently transferred some of its mass to its companion, the other star.

The two stars would be around the same age, so the more massive one would have turned into a giant first before the other one did or even had a chance to

Answer:

The magnetic field is [tex]B = 2.319 *10^{-3} \ T[/tex]

Explanation:

From the question we are told that

   The radius of the wire is [tex]r = 0.8 \ cm = 0.008 \ m[/tex]

    The current is [tex]I = 106 \ A[/tex]

    The position considered is  d = 0.07 cm = 0.0007 m

 Generally the magnetic field is mathematically represented as

         [tex]B = \frac{\mu_o * I}{2\pi * \frac{r^2}{d} }[/tex]

Here [tex]\mu_o[/tex] is the permeability of free space with value [tex] 4\pi * 10^{-7} N/A^2[/tex]

So    

        [tex]B = \frac{ 4\pi * 10^{-7} * 106 }{2 * 3.142 * \frac{0.008^2}{0.0007} }[/tex]

=>     [tex]B = 2.319 *10^{-3} \ T[/tex]

Answer:

The nonconservative work was done on the boy is 1154.87 J.

Explanation:

Given;

mass of the boy, m = 67.6 kg

initial speed of the boy, u = 1.56 m/s

height of fall, h = 1.65 m

final speed of the boy, v = 8.30 m/s

The initial energy of the boy is given by;

E₁ = K.E₁ + P.E₁

E₁ = ¹/₂mu² + mgh

E₁ = ¹/₂(67.6)(1.56)² + (67.6 x 9.8 x 1.65)

E₁ = 82.134 + 1091.475

E₁ = 1,173.61 J

The final energy of the boy is given by;

E₂ = K.E₂

E₂ = ¹/₂mv²

E₂ = ¹/₂(67.6)(8.3)²

E₂ = 2,328.482 J

The nonconservative work was done on the boy is given by;

W = E₂- E₁

W = 2,328.482 J - 1,173.61 J

W = 1154.87 J

Therefore, the nonconservative work was done on the boy is 1154.87 J.

Answer:

Yuh

Explanation:

Answer:

18 m/s

Explanation:

1.8 meters / 0.1 seconds = 18 m/s

Answer:

5N

Explanation:

Given parameters:

Original length = 22cm

Spring constant, K  = 50N/m

New length = 32cm

Unknown

Force applied  = ?

Solution:

The force applied on a spring can be derived using the expression below;

   Force  = KE

 k is the spring constant

 E is the extension

  extension = new length - original length

  extension  = 32cm  - 22cm  = 10cm

convert the extension from cm to m;  

   100cm  = 1m;

    10cm will give 0.1m

So;

  Force  = 50N/m x 0.1m  = 5N

Answer:

The induced current is  [tex]I = 0.00066 \ A[/tex]

Explanation:

From the question we are told that

   The area is  [tex]A = 7.10 \ cm^2 = 7.10 *10^{-4} \ m^2[/tex]

   The initial  magnetic field is  [tex]B_i = 0.500 \ T[/tex]

    The magnetic field after t =1.07 s is  [tex]B_f = 2.10 \ T[/tex]

     The resistance of the loop is [tex]R = 1.60 \ \Omega[/tex]

Generally the electromagnetic field induced is mathematically represented as

   [tex]\epsilon = NA * \frac{B_f - B_i}{t}[/tex]

Where N is the number of turns which is 1 in the case of this question since there is only one loop

 So

       [tex]\epsilon = 1 * 7.10*10^{-4}* \frac{2.10 - 0.500}{1.07 }[/tex]

=>   [tex]\epsilon = 0.00106 \ V[/tex]

Generally the value of the current is mathematically represented as

        [tex]I = \frac{\epsilon}{R}[/tex]

       [tex]I = \frac{0.00106}{1.60}[/tex]

       [tex]I = 0.00066 \ A[/tex]

Answer:

a.  -4.166 J/K

b. 8.37 J/K

c. 4.21 J/K

d. entropy always increases.

Explanation:

Given :

Temperature at hot reservoir , [tex]$T_h$[/tex] = 720 K

Temperature at cold reservoir , [tex]$T_c$[/tex] = 358 K

Transfer of heat, dQ = 3.00 kJ = 3000 J

(a). In the hot reservoir, the change of entropy is given by:

[tex]$dS_h= -\frac{dQ}{t_h}$[/tex]              (the negative sign shows the loss of heat)

[tex]$dS_h= -\frac{3000}{720}$[/tex]

      =  -4.166 J/K

(b)  In the cold reservoir, the change of entropy is given by:

[tex]$dS_c= \frac{dQ}{t_c}$[/tex]              

[tex]$dS_c= \frac{3000}{358}$[/tex]

      =  8.37 J/K

(c). The entropy change in the universe is given by:

[tex]$dS=dS_h+dS_c$[/tex]

    = -4.16+8.37

   = 4.21 J/K

(d). According to the concept of entropy, the entropy of the universe is always increasing and never decreasing for an irreversible process. If the entropy of universe decreases, it violates the laws of thermodynamics. Hence, in part (c), the result have to be positive.

Answer:

the correct answer is D,  acceleration of gravity

Explanation:

In a projectile launch problem it is described by the expressions

        v = v₀ - g t

         v² = v₀² - 2 g y

        y = v₀ t - ½ g t²

By examining these equations we can see that acceleration is the magnitude that appears constant in all expressions.

 This acceleration is the acceleration of gravity with a value of g = 9.8 m/s² and directed towards the center of the Earth

therefore the correct answer is D

Answer:

F = 5.4 x 10⁻⁸ N

Explanation:

The gravitational force of attraction between two objects is given by Newton's Gravitational Law as follows:

F = Gm₁m₂/r²

where,

F = Gravitational Force = ?

G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²

m₁ = mass of student = 92 kg

m₂ = mass of pizza slice = 550 g = 0.55 kg

r = distance between student and pizza slice = 25 cm = 0.25 m

Therefore,

F = (6.67 x 10⁻¹¹ N.m²/kg²)(92 kg)(0.55 kg)/(0.25 m)²

F = 5.4 x 10⁻⁸ N

Answer:

Explanation:

Bones grow in length at the epiphyseal plate by a process that is similar to endochondral ossification. The cartilage in the region of the epiphyseal plate next to the epiphysis continues to grow by mitosis. The chondrocytes, in the region next to the diaphysis, age and degenerate.

Answer:

c. speed

Explanation:

Speedometer is a device used to measure the speed of a vehicle. I am pretty sure this is the correct option.

Answer:

37.3ml

Explanation:

87.3 ml-50 ml=37.3ml

Answer:

ok

Explanation:

g

Answer:

156watts

Explanation:

M = 20

U = 0.200

Vo = 8.0

We are to get p

P = w/t

W = 1/2(vf²-Vo²)

The final velocity is 0

W =-1/2*20*8²

= -640J

Acceleration = -ug

= -0.200*9.8

= -1.96m/s^-2

We are to get t

t = 8/1.96

= 4.1s

P = w/t

= 640/4.1

= 156 watts

156watts is the average power that is produced by friction as the rock stops.

Answer:

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question we have

force = 976 × 2.5

We have the final answer as

Hope this helps you

Answer:

why do you think the senate changed the way it voted? What methods did the suf

why do you think the senate changed the way it voted? What methods did the suffragis

why do you think the senate changed the way it voted? What methods did the suffragists use to influence this change?

Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?

hi

lolTwo manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?ts use to influence this change?

hi

lolfragists use to influence this change?

Explanation:

Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?

lol

Answer:

Newton's theory because he suggested that the greater the distance between objects, the weaker the pull of gravity.

Answer: The answer is Newton’s theory because he suggested that the greater the distance between objects, the weaker the pull of gravity

Explanation: Just took the test i hope this help you enjoy :D

Answer:

The kinetic energy of an electron in the beam is 5.04 keV.

Explanation:

We need to find the velocity of the electron by using the De Broglie wavelength:

[tex] \lambda = \frac{h}{mv} [/tex]

Where:

λ: is the wavelength = 0.0173 nm

v: is the velocity

m: is the electron's mass = 9.1x10⁻³¹ kg

h: is the Planck constant = 6.62x10⁻³⁴ J.s

[tex] v = \frac{h}{m\lambda} = \frac{6.62 \cdot 10^{-34} J.s}{9.1 \cdot 10^{-31} kg*0.0173 \cdot 10^{-9} m} = 4.21 \cdot 10^{7} m/s [/tex]

Now, we can find the kinetic energy:

[tex] E_{k} = \frac{1}{2}mv^{2} = \frac{1}{2}9.1 \cdot 10^{-31} kg*(4.21 \cdot 10^{7} m/s)^{2} = 8.06 \cdot 10^{-16} J*\frac{1 eV}{1.6 \cdot 10^{-19} J} = 5038 eV = 5.04 keV [/tex]

Therefore, the kinetic energy of an electron in the beam is 5.04 keV.

I hope it helps you!

Answer:

The vertical speed in mi/h is 42.

Explanation:

Rectangular Components of a Vector

A 2D vector can be expressed in several forms. The rectangular form gives its two components, one for each axis (x,y). The polar form gives the components as (r,θ) being r the magnitude and θ the angle.

The relationships between the coordinates of both systems are shown in the image below.

When the magnitude and angle of the vector are given, the rectangular components are calculated as follows:

[tex]v_x=v\cos\theta[/tex]

[tex]v_y=v\sin\theta[/tex]

Where v is the magnitude of the vector and θ is the angle with respect to the x positive direction.

We are given the magnitude of the velocity (the speed) at which a plane is moving as v=100 mi/h at an angle of θ=25°, the vertical component of the velocity is:

[tex]v_y=100\sin 25^\circ[/tex]

Calculating:

[tex]v_y=42.26\approx 42[/tex]

The vertical speed in mi/h is 42.

Answer:

Explanation:

initial velocity u = 32.7 m /s

final velocity v = 50.3 m /s

displacement s = 44500 m

acceleration a = ?

v² = u² + 2 a s

50.3² = 32.7² + 2 x a x 44500

2530.09 = 1069.29 + 89000a

a .016 m /s²

time taken t = ?

v = u + at

50.3 = 32.7 + .016 t

t = 1100 s