A vehicle hits a bridge abutment at a speed estimated by
investigations as 20kmph. Skid marks of 30m on pavement
(f=0.35) followed by skid marks of 60m.on the gravel shoulder
approaching the abutment (f=0.50).What was the initial speed of vechile​

Answer:

Wedge

Explanation:

A knife is used to cut things into pieces or even cut two items apart.

Now, it is classified as a Wedge because a Wedge is defined as a simple machine that is used in pushing two objects apart. Some examples include axes, knives & chisels.

Answer:

Epot = 294300 [J]

Explanation:

Potential energy is defined as the product of mass by height by gravitational acceleration. The height is measured with respect to the reference level. At this reference level the potential energy is equal to zero.

[tex]E_{pot}=m*g*h\\[/tex]

where:

m = mass = 150 [kg]

g = gravity acceleration [m/s²]

h = elevation = 200 [m]

[tex]E_{pot}=150*9.81*200\\E_{pot}=294300 [J][/tex]

Answer:

0.426 volts

Explanation:

It is given that,

The radius of a circular loop, r = 11.2 cm = 0.112 m

An elastic conducting material is stretched into a circular loop.

It is placed with its plane perpendicular to a uniform 0.880 T magnetic field.

The radius of the loop starts to shrink at an instantaneous rate of 68.8 cm/s, dr/dt = 0.688 m/s

We need to find the emf induced in the loop at that instant.

[tex]\epsilon=\dfrac{-d\phi}{dt}\\\\=\dfrac{d}{dt}(BA)\\\\=\dfrac{d}{dt}(\pi r^2 B)\\\\=\pi B\dfrac{d}{dt}(r^2)\\\\=2\pi B r\dfrac{dr}{dt}\\\\=2\pi \times 0.88\times 0.112\times 0.688\\\\=0.426\ V[/tex]

So, the magnitude of induced emf is 0.426 volts.

Answer:

(C). The magnitude of electric force acting on the raindrop is 0.1 N.

Explanation:

Given;

charge of the raindrop, Q = 10  μC = 10 x 10⁻⁶ C

electric field strength, E = 10,000 V/m

The electric force acting on the raindrop is given as;

F = EQ

where;

F is the electric force

Substitute the given values and solve for F.

F = (10,000)(10 x 10⁻⁶)

F = 0.1 N

Therefore, the magnitude of electric force acting on the raindrop is 0.1 N.

Answer:

The water kept in an earthen pot seeps into the small pores in the pot and evaporates from the surface of the pot. The heat required for evaporation is taken from water inside the pot, thus cooling the water stored inside. This is the reason why on hot summer days water remains cool in earthen pot.

Answer:

0.63 s

Explanation:

From the question given above, the following data were obtained:

Mass (m) = 50 g

Extention (e) = 10 cm

Period (T) =?

Next, we obtained 50 g to Kg. This can be obtained as follow:

1000 g = 1 Kg

Therefore,

50 g = 50 g × 1 Kg / 1000 g

50 g = 0.05 kg

Next, we shall convert 10 cm to m. This is illustrated below:

100 cm = 1 m

Therefore,

10 cm = 10 cm × 1 m / 100 cm

10 cm = 0.1 m

Next, we shall determine the force exerted on the spring. This can be obtained as follow:

Mass = 0.05 Kg

Acceleration due to gravity (g) = 9.8 m/s²

Force (F) =?

F = mg

F = 0.05 × 9.8

F = 0.49 N

Next, we shall determine the spring constant of the spring.

Extention (e) = 0.1 m

Force (F) = 0.49 N

Spring constant (K) =?

F = Ke

0.49 = K × 0.1

Divide both side by 0.1

K = 0.49 /0.1

K = 4.9 N/m

Finally, we shall determine the period as follow:

Mass = 0.05 Kg

Spring constant (K) = 4.9 N/m

Pi (π) = 3.14

Period (T) =?

T = 2π√(m/k)

T = 2 × 3.14 × √(0.05 / 4.9)

T = 6.28 × √(0.05 / 4.9)

T = 0.63 s

Thus, the period of oscillation is 0.63 s

Answer:

acceleration remains constant at g= 9.8m/s²

velocity however ...increases

Answer:

i) x = 13

ii) x = -1

iii) x = 2

Explanation:

Given the following expressions, we are to find the corresponding value of x.

1) x-1 by 4=3

x-1/4=3

Cross multiply

x-1 = 4*3

x-1 = 12

x = 12+1

x = 13

2) Given 3x+6 by 2 = 3 by 2

3x+6/2=3/2

Cross multiply

2(3x+6) = 2(3)

2(3x) + 2(6) = 6

6x + 12 = 6

6x = 6-12

6x = -6

x = -6/6

x = -1

3) 3x-1by5=2x+3by7​

This can also be written as:

(3x-1)/5 = (2x+3)/7​

Cross multiply

7(3x-1) = 5(2x+3)

Open the bracket

7(3x) - 7(1) = 5(2x) + 5(3)

21x - 7 = 10x + 15

Collect like terms

21x - 10x = 15 + 7

11x = 22

x = 22/11

x = 2

Given that,

The acceleration of gravity is -9.8 m/s²

Initial velocity, u = 39.2 m/s

Time, t = 2 s

To find,

The final velocity of the shot.

Solution,

Let v is the final velocity of sling shot. Using first equation of motion to find it.

v = u +at

Here, a = -g

v = u-gt

v = (39.2)-(9.8)(2)

v = 19.6 m/s

So, its velocity after 2 seconds is 19.6 m/s.

Answer:

The weight is defined as:

W = m*g

where:

m = mass

g = gravitational acceleration.

We know that in Earth the astronaut weights 190 lb-f (this is force, not mass, the correct unit here is 190 lb*m/s^2)

then:

190 lb*m/s^2 = m*9.8m/s^2

(190 lb*m/s^2)/(9.8m/s^2) = 19.39 lb

Now we know the mass of the astronaut.

a) wieght on the moon in Newtons.

Newtons uses kilograms as the units of mass, then we need to rewrite the mass of the astronaut in kg.

we know that 1lb = 0.454 kg

Then 19.39 lb is equal to: 19.39*0.454 kg = 8.8 kg

We know that the acceleration due to gravity on the Moon is one-sixth that on Earth.

then: g = (9.8m/s^2)/6

And the weight of the astronaut in the moon will be:

W = 8.8 kg*(9.8m/s^2)/6 = 14.37 N

b) The weight on mars, where the acceleration due to gravity is 0.38 times that on Earth, we have:

g = (9.8m/s^2)*0.38

then the weight will be:

W = 8.8kg*(9.8m/s^2)*0.38 = 32.77 N

Answer:

(4xy+5ab)(4xy-5ab)

Explanation:

16[tex]x^{2}[/tex][tex]y^{2}[/tex]-25[tex]a^{2}[/tex][tex]b^{2}[/tex]

4^2 is 16 and 5^2 is 25,

Also, (x-a)(x+a) = x^2-a^2

So, this factorized is:

(4xy+5ab)(4xy-5ab)

Hope this helps!

Answer:

The current is  [tex]I_b = 400 \ A[/tex]

Explanation:

From the question we are told that

    The  length of the segment is  [tex]l = 2.50 \ m[/tex]

     The current is  [tex]I_a = 1000 \ A[/tex]

     The force felt is  [tex]F = 4.0 \ N[/tex]

        The distance of the second wire is  [tex]d = 5.0 \ cm = 0.05 \ m[/tex]

Generally the current on the second wire is mathematically represented as

        [tex]I_b = \frac{2 \pi * r * F }{ l * \mu_o * I_a }[/tex]

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

=>      [tex]I_b = \frac{2 * 3.142 * 0.05 * 4 }{ 2.50 * 4\pi *10^{-7} * 1000 }[/tex]

=>      [tex]I_b = 400 \ A[/tex]

Answer:

312hz

Explanation:

thanks me later

Answer: 15m/s

Explanation: Average Velocity is vector describing the total displacement of an object and the time taken to change its position. It is represented as:

[tex]v=\frac{\Delta x}{\Delta t}[/tex]

At t₁ = 1.0s, displacement x₁ is:

[tex]x(1)=25+3(1)^{2}[/tex]

x(1) = 28

At t₂ = 4.0s:

[tex]x(4)=25+3(4)^{2}[/tex]

x(4) = 73

Then, average speed is

[tex]v=\frac{73-28}{4-1}[/tex]

v = 15

The average velocity of a car between t₁ = 1s and t₂ = 4s is 15m/s

Answer:

0.32m/s2

Explanation:

obtained from a=wr2 where w=anular speed

r-radius

Centripetal acceleration refers to the acceleration experienced by an object moving in a circular path. The centripetal acceleration of the ball is approximately [tex]9.86 m/s^2.[/tex]

Centripetal acceleration is a result of the inward force known as the centripetal force that keeps the object moving in a curved path. This force is necessary to counteract the tendency of the object to move in a straight line tangent to the circle.

To find the centripetal acceleration of the ball, we can use the formula:

centripetal  acceleration = [tex](angular speed)^2 * radius[/tex]

First, let's convert the angular speed from revolutions per second to radians per second. Since 1 revolution is equal to [tex]2\pi[/tex] radians, we have:

angular speed in radians per second = [tex]0.500 rev/s * 2\pi rad/rev[/tex]

angular speed in radians per second =[tex]\pi rad/s[/tex]

Now, we can substitute the values into the formula to calculate the centripetal acceleration:

centripetal acceleration = [tex](\pi rad/s)^2 * 0.800 m[/tex]

centripetal acceleration = [tex]\pi ^2 * 0.800 m[/tex]

Using the approximation[tex]\pi = 3.14[/tex], we can calculate the centripetal acceleration:

centripetal acceleration = [tex](3.14)^2 * 0.800 m[/tex]

centripetal acceleration =[tex]9.86 m/s^2[/tex]

Therefore, the centripetal acceleration of the ball is approximately [tex]9.86 m/s^2.[/tex]

For more details regarding centripetal acceleration, visit:

https://brainly.com/question/17123770

#SPJ2

Answer:

 Q = 3.33 108 J

Explanation:

This is an exercise in thermodynamics, specifically isobaric work

        W = V ([tex]P_{f}[/tex]- P₀)

They tell us that we have ⅓ of the volume of the container filled with water

        V = ⅓ 100

         V = 33.3 m³

let's calculate

        W = 33.3 (90-100) 10⁶

        W = - 3.33 10⁸ J

To bring the system to its initial condition if we use the first law of thermodynamics

            ΔE  = Q + W

as we return to the initial condition the change of internal energy (ΔE) is zero

          W = -Q

therefore the required heat is

         Q = 3.33 108 J

The question is incomplete. Here is the complete question.

Suppose the mass of a loaded elevator is 1600 kg.

(a) What force, in Newtons, must be supplied by the elveator's cable to produce an acceleration of 0.745 m/s² upwards against a 185N frictional force?

(b) How much work, in joules, is done by the cable in lifting the elevator 21m?

(c) What is the final speed, in meters per second, of the elevator if it starts from rest?

(d) How much work, in kilojoules, went into thermal energy produced by friction?

Answer: (a) F = 1377 N

              (b) W = 28917 J

              (c) v = 5.6 m/s

              (d) W = 3.885 kJ

Explanation:

(a) According to Newton's Second Law: [tex]F_{net}=m.a[/tex], in which, [tex]F_{net}[/tex] is the vetorial sum of all the forces in a system and its unit is [F] = kg.m/s² or newton (N).

In the elevator's case, and assuming going upwards is positive:

[tex]F-F_{f}=m.a[/tex]

F - 185 = 1600(0.745)

F = 1377 N

For an elevator to produce an acceleration of 0.745m/s² upwards, the cables have to supply a force of 1377 newtons.

(b) Work is the energy transferred to an object while is being moved. It is calculated as: W = F.s. Its unit is [W] = N.m or Joule (J)

In the elevator's cable:

W = 1377.21

W = 28917 J

The work done by the elevator's cable is W = 28917 joules.

(c) Acceleration is variation in velocity along time. Since we know the displacement of the elevator:

[tex]v^{2}=v_{0}^{2}+2a\Delta x[/tex]

where:

v₀ is initial velocity, which is this case v₀=0 because it starts from rest;

a is acceleration;

Δx is the displacement

Replacing values:

[tex]v^{2}=2(0.745)(21)[/tex]

[tex]v=\sqrt{31.29}[/tex]

v = 5.6 m/s

Final speed of the elevator is 5.6 m/s.

(d) [tex]W=F_{f}.s[/tex]

W = 185(21)

W = 3885 J

Work transferred into thermal energy because of friction is W = 3.885 kJ.

Answer:

Telescopes have changed the way scientists study the Solar System. Before telescopes, people were only able to observe the Universe with their naked eyes. ... If it were not for telescopes, scientists would not be able to detect possible threats to Earth or predict comet's sightings.

Explanation:

400 years ago, before telescopes, our understanding of the universe was very different.

This is what was believed:

We live on a spherical ball orbited by the rest of a finite, spherical universe.

Earth does not move. It is the center of the universe.

Our Sun orbits the Earth, as do all the other planets and the Moon.

The stars are distant objects, always perfect and unchanging.

How did telescopes & associated technologies unlock the secrets of the universe and

help us toward the understanding we have today where Earth is no longer at the center of

the universe? Instead, we know that ours is a small planet orbiting a star in the suburbs

of a large galaxy filled with billions of other stars and planets, surrounded by billions of

other galaxies becoming increasingly ever distant from each other by the expansion of

space.

This is the story of how telescopes continuously changed our understanding of the

universe and our place in it - transforming our view of our universe. And we still have

much more to discover!

2. Before telescopes, we could only use our eyes and a variety of measuring instruments to

plot the positions and movements of objects in the sky to create a limited understanding

of our universe. We had no way to know what these objects actually were and little

evidence for our relationship to the cosmos.

Answer:

The magnitude of the frictional force is 50 newtons.

Explanation:

The frictional force can be found as follows:

[tex] \Sigma F = ma [/tex]

[tex] F - F_{\mu} = ma [/tex]

Where:

F: is the applied force = 50 N

[tex]F_{\mu}[/tex]: is the frictional force

m: is the box's mass

a: is the acceleration

Since the box is pulled at a constant velocity, a = 0, so:

[tex] F - F_{\mu} = 0 [/tex]

[tex] F = F_{\mu} = 50 N [/tex]

Therefore, the magnitude of the frictional force is equal to the applied force, that is to say, 50 newtons.

I hope it helps you!                                                                                

Explanation:

Given:

Acceleration of car = 10 m/s

Distance travelled in 5 sec = 150 m

To find:

Distance travelled in the next 5 seconds

Concept:

There are 2 ways to app this kind of questions .

Either , we can find the total distance travelled in 10 seconds and then subtract 150 m from it.

Whereas , you can find out the final velocity at the end of the 5th seconds. Using equation of motion, then get the distance travelled in next 5 seconds.

Calculation:

v² = u² + 2as

=> ( u + at)² = u² + 2as

=> u² + 2uat + a²t² = u² + 2as

=> 2uat + (at)² = 2as

=> 2u (10)(5) + (10 × 5)² = 2 (10)(150)

=> 100u = 3000 - 2500

=> 100u = 500

=> u = 5 m/s

Distance travelled in 10 seconds :

s = ut + ½at²

=> s = (5 × 10) + ½(10)(10)²

=> s = 50 + 500

=> s = 550 m

Distance travelled in the 2nd half will be :

d = 550 - 150

=> d = 400 m

So final answer is :

Answer:

a

 [tex]A = 0.081 \ m[/tex]

b

The value is  [tex]u = 0.2569 \ m/s[/tex]

Explanation:

From the question we are told that

   The mass is  [tex]m = 0.750 \ kg[/tex]

   The spring constant is  [tex]k = 17.5 \ N/m[/tex]

    The instantaneous speed is  [tex]v = 39.0 \ cm/s= 0.39 \ m/s[/tex]

    The position consider is  x =  0.750A  meters from equilibrium point

Generally from the law of  energy conservation we have that

        The kinetic energy induced by the hammer  =  The energy stored in the spring

So

          [tex]\frac{1}{2} * m * v^2 = \frac{1}{2} * k * A^2[/tex]

Here a is the amplitude of the subsequent oscillations

=>      [tex]A = \sqrt{\frac{m * v^ 2 }{ k} }[/tex]

=>      [tex]A = \sqrt{\frac{0.750 * 0.39 ^ 2 }{17.5} }[/tex]

=>       [tex]A = 0.081 \ m[/tex]

Generally from the law of  energy conservation we have that

The kinetic energy  by the hammer  =  The energy stored in the spring at the point considered   +   The kinetic energy at the considered point

             [tex]\frac{1}{2} * m * v^2 = \frac{1}{2} * k x^2 + \frac{1}{2} * m * u^2[/tex]

=>          [tex]\frac{1}{2} * 0.750 * 0.39^2 = \frac{1}{2} * 17.5* 0.750(0.081 )^2 + \frac{1}{2} * 0.750 * u^2[/tex]

=>          [tex]u = 0.2569 \ m/s[/tex]

Answer:

approximately 150 grams

Explanation:

The weight of an object is a product of its mass and acceleration of gravity acting upon it. Since weight (W) is force, it is measured in Newtons (N) or Kgms-²

W = mg

Where;

W = weight (N)

m = mass (kg)

g = acceleration due to gravity

g is a constant, which is approximately 10m/s²

Therefore, according to this question, the mass of a bag of shells that weighs 1.5N can be calculated thus:

m = W/g

m = 1.5/10

m = 0.15 kg

Converting 0.15kg to grams, we multiply by 1000 i.e 0.15 × 1000 = 150 grams.

Hence, the mass of the object is approximately 150grams.

Answer:

0.06 Kg

Explanation:

From the question given above, the following data were obtained:

Initial velocity (u) = 0 m/s

Final velocity (v) = 3.0 m/s

Distance (s) = 0.09 m

Net Force (F) = 3 N

Mass (m) =?

Next, we shall determine the acceleration of the object. This can be obtained as follow:

Initial velocity (u) = 0 m/s

Final velocity (v) = 3.0 m/s

Distance (s) = 0.09 m

Acceleration (a) =?

v² = u² + 2as

3² = 0² + (2 × a × 0.09)

9 = 0 + 0.18a

9 = 0.18a

Divide both side by 0.18

a = 9 / 0.18

a = 50 m/s²

Finally, we shall determine the mass of the object. This can be obtained as follow:

Net Force (F) = 3 N

Acceleration (a) = 50 N

Mass (m) =?

F = ma

3 = m × 50

Divide both side by 50

m = 3 / 50

m = 0.06 Kg

Therefore, the mass of the object is 0.06 Kg

The required value for the mass of object is 0.06 kg.

Given data:

The speed of object is, v = 3.0 m/s.

The distance travelled by object is, s = 0.090 m.

From the given graph in the question, we obtain the following details as,

The net force applied on the object is, [tex]F_{net}=3\;\rm N[/tex].

The initial velocity is, u = 0 m/s.

Now using the third kinematic equation of motion to obtain the acceleration of object as,

v² = u² + 2as

3² = 0² + (2 × a × 0.09)

9 = 0 + 0.18a

9 = 0.18a

Solving as,

a = 9 / 0.18

a = 50 m/s²

Now, as per the Newton's second law of motion, we have the expression for the applied force as,

[tex]F_{net}= ma[/tex]

Here, m is the mass of object.

Solving as,

[tex]3= m \times 50\\\\m = 0.06 \;\rm kg[/tex]

Thus, we can conclude that the required value for the mass of object is 0.06 kg.

Learn more about the Newton's second law here:

https://brainly.com/question/19860811

Answer:

The answer is  "-72 k".

Explanation:

Please find the complete question in the attached file.

Given point:

[tex]A=(0,0,0)\\B=(0,8,0)\\C=(9,8,0)\\D=(9,0,0)[/tex]

[tex]\bar{AB} = (0i+8j+0k)-(0i+0j+0k)= 8j\\\\\bar{AC} = (9i+8j+0k)-(0i+0j+0k)= 9i+8j\\\\[/tex]

Calculating the area:

[tex]Area=\left|\begin{array}{ccc}i&j&k\\0&8&0\\9&8&0\end{array}\right|[/tex]

       [tex]=i[8(0)-8(0)]-j[(0-0)]+k[(0-9(8))]\\\\=i[0-0]-j[(0)]+k[(0-72)]\\\\=i[0]-j[(0)]+k[(-72)]\\\\=-72 \ k[/tex]

Answer:

h = 5.09 m

Explanation:

Applying the Law of conservation of energy to this situation, we can write:

[tex]Kinetic\ Energy\ Gained\ by\ the\ Cart = Potential\ Energy\ Lost\ by\ the\ Cart\\\frac{1}{2}mv^2 = mgh\\\\h = \frac{v^2}{2g}[/tex]

where,

h = height of the hill = ?

v = speed of cart at the end = 10 m/s

g = acceleration due to gravity = 9.81 m/s²

Therefore,

[tex]h = \frac{(10\ m/s)^2}{(2)(9.81\ m/s^2)}\\\\[/tex]

h = 5.09 m

Answer:

umm  becuase it is a test and you need them

Explanation:

Answer:

[tex]E = -6 \ N/C[/tex]

Generally given that the electric field is negative it mean that its direction is opposite to that of the force    

Explanation:

From the question we are told that

   The charge on the small object is [tex]Q = -4.00 \ nC = -4.00 *10^{-9} \ C[/tex]

   The force is  [tex]F = 24 \ nN = 24 *10^{-9} \ N[/tex]

    Generally the magnitude of the electric  field is mathematically represented as

       [tex]E = \frac{F}{Q}[/tex]

=>    [tex]E = \frac{ 24 *10^{-9}} {-4 *10^{-9 }}[/tex]

=>     [tex]E = -6 \ N/C[/tex]

Generally given that the electric field is negative it mean that its direction is opposite to that of the force