A block slides along a frictionless surface and onto a slab with a rough surface. The slab has mass of 4 kg and the block has mass of 2 kg. What is the friction force on the small block at t = 1 second?

Answer:

VAB = 20km/hr

Explanation:

Given the following data;

Velocity of car A, VA = 60km/hr

Velocity of car B, VB = 80km/hr

To find the relative velocity of B w.r.t A, VAB;

Since the two cars are moving in the same direction, we have;

VAB = VB - VA

Substituting into the equation, we have;

VAB = 80 - 60

VAB = 20km/hr

Therefore, the relative velocity of car B with respect to car A is 20 kilometers per hour.

Answer:

B

Explanation:

B is the most likely region that contains alkaline earth family elements.

The alkaline earth metal family of elements is represented by B region in the figure.

The alkaline earth metals are found on the periodic table in Group 2, which is on the far left side of the table between Group 1, the alkali metals, and Groups 3-12, the transition elements. This family is made up of six metals: beryllium, magnesium, calcium, strontium, barium, and radium.

The periodic table, also known as the periodic table of the elements, is a tabular display of the chemical elements.

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Answer:

i think its D

Explanation:

Answer:

v= 17.15 m/s

Explanation:

mass of the book=0.1 Kg

height above ground, h= 15 m

Using conservation of energy

Potential energy is converted into kinetic energy

[tex]mgh = \frac{1}{2}mv^2[/tex]

[tex]v=\sqrt{2gh}[/tex]

[tex]v=\sqrt{2\times 9.8\times 15}[/tex]

[tex]v=\sqrt{294}[/tex]

v= 17.15 m/s

Hence, the book will hit the ground at the speed of 17.15 m/s.

Answer:

h = 9.83 cm

Explanation:

Let's analyze this interesting exercise a bit, let's start by comparing the density of the ball with that of water

let's reduce the magnitudes to the SI system

         r = 10 cm = 0.10 m

         m = 10 g = 0.010 kg

         A = 100 cm² = 0.01 m²

the definition of density is

          ρ = m / V

the volume of a sphere

         V = [tex]\frac{4}{3} \ \pi r^{3}[/tex]

          V = [tex]\frac{4}{3}[/tex] π 0.1³

          V = 4.189 10⁻³ m³

let's calculate the density of the ball

           ρ = [tex]\frac{0.010}{4.189 \ 10^{-3} }[/tex]

           ρ = 2.387 kg / m³

the tabulated density of water is

         ρ_water = 997 kg / m³

we can see that the density of the body is less than the density of water. Consequently the body floats in the water, therefore the water level that rises corresponds to the submerged part of the body. Let's write the equilibrium equation

            B - W = 0

            B = W

where B is the thrust that is given by Archimedes' principle

           ρ_liquid  g V_submerged = m g

           V_submerged = m / ρ_liquid

we calculate

            V _submerged = 0.10 9.8 / 997

             V_submerged = 9.83 10⁻⁴ m³

The volume increassed of the water container

           V = A h

            h = V / A

let's calculate

            h = 9.83 10⁻⁴ / 0.01

            h = 0.0983  m

this is equal to h = 9.83 cm

Answer:

Here you go, hope this helps! :)

Explanation:

Opportunity cost is the value of the next best thing you give up whenever you make a decision. It is "the loss of potential gain from other alternatives when one alternative is chosen". ... For example, opportunity cost is how much leisure time we give up to work.

Answer:

Puck 1 = 12 m/s

Explanation:

Conservation of energy

KE_1a + KE_2a = KE_1b + KE_2b

(1/2)(0.1kg)(15m/s)^2 + (1/2)(0.1kg)(12m/s)^2 = (1/2)(0.1kg)(V)^2 + (1/2)(0.1kg)(15m/s)^2

V = 12m/s

Answer:

12 m/s west

Explanation:

just did it

Answer:

t = 3/8 seconds

Explanation:

h=-16t^2 - 10t+6

h= 0 when it hits the ground

0=-16t^2 - 10t+6

factor out a -2

0= -2(8t^2 +5t -3)

divide by -2

0 = (8t^2 +5t -3)

factor

0=(8t-3) (t+1)

using the zero product property

8t-3 = 0    t+1 =0

8t = 3         t= -1

t = 3/8     t= -1

t cannot be negative  ( no negative time)

t = 3/8 seconds

question: is this actually hypothetical?

Explanation:

also just leave the car there go get some McDonald's or sum and come back and if they're still breathing then go ahead and move the car .

Answer:

the same thing the last guy said

Answer: 10

Explanation:

The mechanical advantage of that pulley is 10.

The force amplified by utilizing a tool, mechanical device, or machine system is known as mechanical advantage. To achieve the desired output force amplification, the gadget trades off input forces against movement. The law of the lever serves as a paradigm for this.

Mechanisms are machine parts made to control forces and motion in this way.

Given that: the weighs of the object: W = 100 Newton.

Applied force: F = 10 N.

For using a pulley, you have to apply a force of 10 Newtons to lift  an object that weighs 100 Newtons.

Hence, the mechanical advantage of the pulley is

= Weighs of the object/applied force

= 100 Newton / 10 Newton.

= 10.

The mechanical advantage of it is 10.

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Answer:

The current value of the Hubble's constant = 73 km/sec/Mpc.

t = 71.9 trillion years will be the new age of universe if the Hubble constant = 700 km/s/Mpc

Explanation:

The current value of the Hubble's constant = 73 km/sec/Mpc. However, recent discoveries in the cosmology contradicts the idea of Hubble constant as being fixed. Some scientists are not agreeing on this value and the debate is going on.

Hubble law states that how fast universe is expanding or in other words, galaxies are expanding separating with a speed directly proportional to the distance of galaxies to the earth.

Hence,

v is directly proportional to d

where, v = apparent velocity

d = distance

if we equate velocity and distance then there comes Hubble constant.

v = [tex]H_{0}[/tex] x d

 [tex]H_{0}[/tex] = 73 km/sec/Mpc

where, Mpc = Mega Parsec = 1 Mpc = 3.086 x [tex]10^{19}[/tex] km      

We can use Hubble constant to tell the age of universe.

t = d/v

t = d/( [tex]H_{0}[/tex] xd)

t = 1/[tex]H_{0}[/tex]

Scientist calculated the age of universe by using Hubble constant, which is 13.4 billion years.

Now, if we hypothetically change the value of Hubble constant,

from [tex]H_{0}[/tex] = 73 km/sec/Mpc to [tex]H_{0}[/tex] = 700 km/sec/Mpc

then the age of universe will be:

t = 1/[tex]H_{0}[/tex]

first convert the units of new [tex]H_{0}[/tex] into 1/s

[tex]H_{0}[/tex] = (700) x (/3.08 x [tex]10^{19}[/tex] )

[tex]H_{0}[/tex] = 227.27 x[tex]10^{-19}[/tex]  = 2.27 x [tex]10^{-21}[/tex] 1/s

So,

Age of universe will be:

t = 1/[tex]H_{0}[/tex] = 1/2.27x[tex]10^{-21}[/tex] 1/s

t = 2.27 x [tex]10^{21}[/tex] s

t = 71.9 trillion years

t = 71.9 trillion years will be the new age of universe if the Hubble constant = 700 km/s/Mpc

Given value:

Hubble Constant,

We know,

By substituting the value of "Mpc" in Hubble constant, we get

→ [tex]H_o = \frac{700}{3.086\times 10^{19}}[/tex]

        [tex]= 227\times 10^{-19} \ 1/s[/tex]

        [tex]= 2.27\times 10^{-21} \ 1/s[/tex]

The Hubble's time will be:

→ [tex]H_o = \frac{1}{t}[/tex]

or,

→ [tex]t = \frac{1}{H_o}[/tex]

     [tex]= \frac{1}{2.27\times 10^{-21}}[/tex]

     [tex]= 4.4\times 10^{20} \ seconds[/tex]

Thus the above approach is right.

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(a) The plane makes 4.3 revolutions per minute, so it makes a single revolution in

(1 min) / (4.3 rev) ≈ 0.2326 min ≈ 13.95 s ≈ 14 s

(b) The plane completes 1 revolution in about 14 s, so that in this time it travels a distance equal to the circumference of the path:

(2π (23 m)) / (14 s) ≈ 10.3568 m/s ≈ 10 m/s

(c) The plane accelerates toward the center of the path with magnitude

a = (10 m/s)² / (23 m) ≈ 4.6636 m/s² ≈ 4.7 m/s²

(d) By Newton's second law, the tension in the line is

F = (1.3 kg) (4.7 m/s²) ≈ 6.0627 N ≈ 6.1 N

Answer:

Ball moves up and down repeatedly on surface because waves consist of successive crests and troughs moving across surface, each crest pushes ball up and each trough allows it to move down.

Explanation:

Answer:

7.97 N

Explanation:

[tex]f = m g sin(\alpha) = 2 * 9.8 * sin(24) = 7.97 N[/tex]

Answer:

27.91ohms

Explanation:

From the question we are given the following

Voltage across the inductor VL = 120V

Current in the inductor I = 4.3A

Required

Inductive reactance XL

Using two formula

VL =IXL

XL = VL/I

XL = 120/4.3

XL = 27.91ohms

Hence the inductive reactance is 27.91ohms

Motion energy is indeed the total of kinetic and potential energies in a workable item. The energy contained in moving things is known as motion energy.

In physics, energy is the capacity to accomplish work. It can be potential, kinetic, thermal, electric, chemical, radioactive, or in other forms. There is also heat and work, which is energy inside the process of being transferred through one body to the other. Energy is always classified according to its type once it has been transmitted.

The energy contained in moving things is known as motion energy, sometimes known as mechanical energy. More energy is saved when the thing goes quicker. Motion energy is indeed the total of kinetic and potential energies in a workable item.

Therefore, motion energy is indeed the total of kinetic and potential energies in a workable item.

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Answer:

The answer is i just need the 5 pt sowwry bro hope you have luck finding it ;]

Explanation:

you prolly alr found it but it doesnt really matter

Answer:

  T₀ = 2π [tex]\sqrt{\frac{m}{k} }[/tex]           T = [tex]\sqrt{\frac{5}{6} }[/tex] T₀

Explanation:

When the block is oscillating it forms a simple harmonic motion, which in the case of a spring and a mass has an angular velocity

        w = [tex]\sqrt{k/m}[/tex]

To apply this formula to our case, let's look for the equivalent constant of the springs.

Let's start with the springs in parallels.

* the three springs in the upper part, when stretched, lengthen the same distance, therefore the total force is

       F_total = F₁ + F₂ + F₃

the springs fulfill Hooke's law and indicate that the spring constant is the same for all three,

       F_total = - k x - k x - kx = -3k x

therefore the equivalent constant for the combination of the springs at the top is

      k₁ = 3 k

* the two springs at the bottom

following the same reasoning the force at the bottom is

        F_total2 = - 2 k x

the equivalent constant at the bottom is

         k₂ = 2 k

now let's work the two springs are equivalent that are in series

the top spring is stretched by an amount x₁ and the bottom spring is stretched x₂

            x₂ = x -x₁

            x₂ + x₁ = x

if we consider that the springs have no masses we can use Hooke's law

            [tex]-\frac{F_{1} }{k_{1} } - \frac{F_{2}}{k_{2} } = \frac{F}{k_{eq} }[/tex]

therefore the equivalent constant is the series combination is

             [tex]\frac{1}{k_{eq} } = \frac{1}{k_{1} } + \frac{1}{k_{2} }[/tex]

we substitute the values

             \frac{1}{k_{eq} }  = \frac{1}{3k } + \frac{1}{2k }  

             \frac{1}{k_{eq} }  = \frac{5}{6k} }  

              k_eq = [tex]\frac{6k}{5}[/tex]  

therefore the angular velocity is

             w = [tex]\sqrt{\frac{6k}{5m} }[/tex]  

angular velocity, frequency, and period are related

           w = 2π f = 2π / T

           T = 2π / w

            T = 2π [tex]\sqrt{\frac{5m}{6k} }[/tex]

           T₀ = 2π [tex]\sqrt{\frac{m}{k} }[/tex]

           T = [tex]\sqrt{\frac{5}{6} }[/tex] T₀

Answer:

If the heavy load had been lifted more slowly, the work done on the load would have been the same.

Explanation:

Work done on an object is given as;

W = Fd

where;

F is the force applied on the object

d is the displacement of the object

for the given question, the applied force on the load = mg (mass of the load multiplied by acceleration due to gravity).

Also, the displacement of the object = vertical height the load was lifted.

W = mgh

The work done on the load is independent of time.

Thus, if the heavy load had been lifted more slowly, the work done on the load would have been the same.

A person lifting a heavy load to a vertical height of 2.0 m in 3 seconds does the same work as if he/she lifts it in 6 s.

A person lifts a heavy load to a vertical height of 2.0 m in 3 seconds.

We want to compare the work done with the one that he/she would have done if the process had taken 6 seconds.

In physics, work (W) is the energy transferred to or from an object via the application of force (F) along a displacement (s).

W = F × s

Given the displacement is the same (2.0 m) and the force needed is also the same (weight of the object), the work is the same for both processes.

A person lifting a heavy load to a vertical height of 2.0 m in 3 seconds does the same work as if he/she lifts it in 6 s.

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Answer:

1. The respiratory system functions when our involuntary nervous system sends impulses to the muscles in the diaphragm; thereby, causing the lungs to expand and contract.

2. The respiratory system oxygenates the blood which is vital for bodily function as oxygenated blood is carried from your lungs to the left side of your heart, to be circulated throughout the body. Furthermore deoxygenated blood is carried back to the right side of your heart to get oxygenated once more.

3. The other body systems that are crucial for the lungs to function are the nervous system and the muscular system.

4. without the raspatory system the body wouldn't receive any oxygen and the brain would slowly die. therefore, without the brain the heart would stop functioning and atrophy etc.

Explanation:

Answer:

The evidence that the universe is expanding comes with something called the red-shift of light. Light travels to Earth from other galaxies. As the light from that galaxy gets closer to Earth, the distance between Earth and the galaxy increases, which causes the wavelength of that light to get longer. Distant galaxies are getting further away hinting at a point of origin. The composition of all observed matter in this universe points at a common origin point for all matter in the universe.

The three crucial evidences that supported the Big Bang theory are the CMB or cosmic microwave background, the expanding universe, the abundance of elements in the universe.

Big Bang theory is one of the important theory scientists used in earliest to describe the origin of universe and the phenomenon of evolution.

Here,

2. The Big Bang theory described the origin of universe as an expansion from an atmosphere of high density and extreme temperature which lead to a huge explosion of matter known as the  'Big Bang' and thus creation of  the universe.

The three crucial evidences that supported the Big Bang theory are:

The CMB or cosmic microwave background, the expanding universe, the abundance of elements in the universe.

3.(a) Light spectra was an important factor that supported the Big Bang theory mainly by the phenomenon called Doppler shift. Doppler shift occurs when stars move away, they get shifted to longer wavelength. This phenomenon is called red-shift or Doppler's Red shift. This was applicable in the case of Big Bang theory such that the theory claimed that, as a result of explosion which is the Big Bang, the material particles move away. This was similar to the red shift.

(b) The motion of distant galaxies was an evidence of the expansion of universe and soo the Big Bang theory. It was explained in such a way that, as the galaxies move away from us, it shows the more expansion of universe and the time duration since the origin of universe.

(c) The composition of matter in the universe was an important evidence that supported the Big Bang theory. The composition of universe that there is high abundance of hydrogen and helium in the atmosphere was claimed by the Big Bang theory.

Hence,

The three crucial evidences that supported the Big Bang theory are the CMB or cosmic microwave background, the expanding universe, the abundance of elements in the universe.

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Answer:

(a) You can tell that have the same strength because they have attracted the same amount of paper clips.

(b) Iron is used in electromagnets because steel retained magnetic properties after the power was turned off, but in the iron, the paper clips dropped off right away.

Answer:

air resistance and gravity.

Explanation:

When the ball is falling down at terminal velocity, the velocity is constant.

This means that the net force acting on the ball will be zero (there is no acceleration)

In this situation, there are only two forces that can act on the ball.

The gravitational force, that pulls the ball down.

The air resistance which opposes to the movement of the ball and increases in magnitude as the velocity of the ball increases.

Then there is a point where the velocity of the ball is such that the air resistance is equal in magnitude to the acceleration, and then the net force becomes zero.

Then the two forces that need to be included in this diagram are the air resistance and gravity.

Answer:-The formula of to calculate  KE = 1/2 m v^2

so we,

           KE = 1/2 (450kg)(23m/s)^2

           KE = 1/2 ×238050

            KE = 119025

Explanation: In Physics Formulas mean everything.

which of the following statements BEST describes the difference between an atom and an ion ?

Answer:

well the correct answer is

Explanation:

A charged atom is known as an ion, well it can be negative as well as positive charge.