A stone of 1 kg is thrown with a velocity of 40 m/s across the frozen surface of a lake and comes to rest after travelling a distance of 50 m. What is the force of friction between the stone and the ice? *

A)16 N
B)-4 N
C)-16 N

​

Explanation:

Let 'F' be force acting perpendicularly, 'A' be the area and 'P' be the pressure exerted.

Then,

Pressure is directly proportional to the the force acting perpendicularly i.e.

P ∝ F ............. (i)

Pressure is inversely proportional to the area on which force acts i.e.

P ∝ 1/A ........... (ii)

Combining equations (i) and (ii),

P ∝ F/A

or, P = K × F/A [where K is a constant]

If F is 1N, A is 1m² and P is 1 N/m², then K is 1.

So, P = F/A proved...

Answer:

A person climbs a set of stairs

Explanation:

Potential energy is said to be possessed by an object due to its position. As the height from the ground level increase, the potential energy increases. It is calculated by the below formula as :

P = mgh

Out of the given options, the option that illustrates an increase in potential energy is option (b) i.e. a person climbs a set of stairs. As he steps one stair, its position from ground increases. It means its potential energy increases.

Answer:

1. option a

2. option d

Explanation:

HOPE IT HELPS YOU

Answer:

yes

Explanation:

because motion is relevant

Answer:

Motion is mathematically defined as displacement, distance, velocity, acceleration, speed, and time. The motion of a body is recognized by adding a frame of reference to an observer and measuring the change in position of the body related to that frame with the change in time.

Answer:

Explanation:

It is the case of perfectly elastic collision . So we shall apply formula of velocity after collision as follows .

Let  m₁ and m₂ be the mass colliding with velocity u₁ and u₂ and their velocity become v₁ and v₂ after collision .

[tex]v_1=\frac{(m_1-m_2)u_1 }{m_1+m_2)} +\frac{2 m_2u_2}{(m_1+m_2)}[/tex]

Putting the values

[tex]v_1=\frac{ (.30-.80).40 }{( .30+.80)} +\frac{2\times .80\times(-.15) }{(.30+.80 )}[/tex]

= - 0.4 m /s

So direction of .30 kg mass will be reversed .

[tex]v_2=\frac{ ( m_2-m_1) u_2 }{( m_1+m_2)} +\frac{2 m_1u_1}{(m_1+m_2)}[/tex]

putting the values

[tex]v_2=\frac{ ( .80-.30)(-.15) }{( .30+.80)} +\frac{2 \times.30\times.40}{(.30+.80)}[/tex]

= .15 m /s

The direction of .80 kg will become from left to right ie its direction will be reversed .

b ) Minimum amount of kinetic energy will be at the position when they move with common velocity

common velocity

v = .3 x .4 - .8 x .15 / (.3 + .8)

= 0

c )

Missing energy is stored as elastic potential energy in the spring .

Answer:

2,500,000W or 2.5MW

Explanation:

The power lost due to resistance is given by I^2R. We must first obtain R as follows;

Resistance per kilometer= 0.050Ω/km

Distance covered= 200km

R = 200km x 0.050Ω/km = 10Ω

The lost power as a 500A current passes through the powerline is:

P = I²R

P= 500² x 10

P= 2,500,000 W or 2.5MW

The resistive power loss in 200 km of the powerline is of 2.5 MW.

Given data:

The root mean square voltage is, V' = 500000 V.

The magnitude of current through the power line is, I =500 A.

The magnitude of resistance of cable is, R = 0.050 Ω/km.

The length of powerline is, L = 200 km.

Whenever there is a flow of current through the wire, then there are various losses out of which the power loss is a major factor. The mathematical expression for the power loss is given as

P = I²R

Solving as,

P= 500² x 10

P= 2,500,000 W or 2.5MW

Thus, we can conclude that the resistive power loss in 200 km of the powerline is of 2.5 MW.

Learn more about the resistive power loss here:

https://brainly.com/question/15158529

Answer:

The magnitude of the resultant of the magnetic field is [tex]4.11\times10^{-5}\ T[/tex]

Explanation:

Given that,

Current = 40 A

Magnetic field [tex]B=3.7\times10^{-5}\ T[/tex]

Distance = 22 cm

We need to calculate the magnetic field

Using formula of magnetic field

[tex]B'=\dfrac{\mu_{0}I}{2\pi r}[/tex]

Where, r = distance

I = current

Put the value into the formula

[tex]B'=\dfrac{4\pi\times10^{-7}\times20}{2\pi\times0.22}[/tex]

[tex]B'=1.8\times10^{-5}\ T[/tex]

We need to calculate the magnitude of the resultant of the magnetic field

Using formula of resultant

[tex]B''=\sqrt{B^2+B'^2}[/tex]

Put the value into the formula

[tex]B''=\sqrt{(3.7\times10^{-5})^2+(1.8\times10^{-5})^2}[/tex]

[tex]B''=4.11\times10^{-5}\ T[/tex]

Hence, The magnitude of the resultant of the magnetic field is [tex]4.11\times10^{-5}\ T[/tex]

Answer:

first part the skater goes down a constant slope ramp, initially he has Newton's second law

pply Newton's third law, the normal is the reaction to the support of the body on the surface

the ramp shoots off.  axis becomes zero and therefore with Newton's first law its speed

Explanation:

It is the description of this movement let's write Newton's laws.

* The first law that a body goes at constant speed or zero if the sum of the external forces is zero

* the second law is F = m a

* The third law states that the forces act in pairs of equal magnitude and opposite direction, one applied to each body.

Let's apply these laws to our case

In the first part the skater goes down a constant slope ramp, initially he has Newton's second law when he accelerates from the initial velocity of zero to a terminal velocity.

The expression for this is

             Wₓ - fr = ma

             W sin θ - μ W cos θ = m a

             W = mg

             g (sin θ - μ cos) = a

the value of the coefficient of kinetic friction depends on the condition of the surface, dry, wet or muddy

This is Newton's second law

On the Y axis, which is perpendicular to the ramp we have

            N- [tex]W_{y}[/tex] = 0

If we apply Newton's third law, the normal is the reaction to the support of the body on the surface, note that it can be different from the weight.

In the second part when he is on the ramp.

In the ramp the skater enters with a speed v, suppose that the ramp has an incline so that the skater can jump, in this case the angle is positive with respect to the axis x

In this case the analysis is similar to the previous one

Newton's second law gives the acceleration of the skater, who when he reaches the end of the ramp shoots off.

 At this point the force in the x (horizontal) axis becomes zero and therefore with Newton's first law its speed this axis remains constant and the force in the y axis is the force of gravity and has an acceleration that changes if velocity according to Newton's second law

Answer:look at explanations

Explanation:

Answer:

h = 35857 km

Explanation:

A geosynchronous orbit can be defined as circular orbit which lies on the Earth's equatorial plane and follows the direction of the Earth's rotation in a period that's equal to the Earth's rotational period and thereby appearing motionless, at a fixed position in the sky relative to the ground observers.

We are given;

Radius of earth(R) = 6.37 x 10^(6) m

Mass of earth (Me) = 5.97 x 10^(24) kg

Gravitational constant = 6.67 × 10^(-11) m³/kg.s²

The earth has a rotational period of 24 hours per day. This gives in seconds

T = 24 × 60 × 60

T = 86400 s

Let's make the height of the orbit from Earth's surface to be h

Also, let ω be the uniform angular velocity in rad/s with which the satellite rotates in the geosynchronous orbit

Now, equating the centripetal force with the gravitational force gives us;

mω²(R + h) = G•Me•m/(R + h)²

m will cancel out. Also ω can be written as 2π/T

Thus,we now have;

(R + h) = ∛(G•Me•T²/(4π²))

Plugging in the relevant values, we have;

(R + h) = ∛(6.67 × 10^(-11) × 5.97 x 10^(24) × 86400²/(4π²))

(R + h) = 42227 Km

Since R = 6.37 x 10^(6)m = 6370 km

Thus;. h = 42227 - 6370 = 35857 km

Answer:

Archaeology

Explanation:

Radioisotopes are radioactive atoms of an element in which their atoms contain excess energy making them unstable. When broken down they become more stable releasing radiations.

Carbon 14 is a radioactive isotope that is used in archaeology to study and estimate the lifespan and age of organic materials such as wood, leather. Carbon 14 can be used to estimate the ages of materials up to 50000 to 60000 years.

Answer:

archaeology

Explanation:

Answer:

[tex]r = \frac{v}{i} = v = ri \\ i = \frac{v}{r} [/tex]

Answ

In real world application Ultraviolet is not a color as it it can’t be seen by the human eye. It is a high frequency part of the Suns electromagnetic radiation. Even though UltraViolet sounds like a color, the Ultra in this case signifies that it is beyond Violet and thus beyond the visible part of the electromagnetic spectrum. They are not depicted with a color on spectrum charts, since we can’t see it we can’t truly classify it as a color no more than can we equate the other parts of the spectrum like XRays, Gamma Rays and Radio Waves with colors. These and other non-visible parts of the spectrum are measured instead with wavelengths. So the answer is no they would not be monochromatic, or any color at all.

Red, Orange, Yellow, Green, Blue, Indigo and Violet are the visible colors of the electromagnetic spectrum. They, combined together are called white light and our atmosphere acts like a prism to divide them into separate and apparently distinct colors. Outside the visible Red you have Infrared which is invisible to the human eye and is the heat we feel from the sun. Outside the Violet end of the visible spectrum is where UVA, UVB and UVC are found, and these are the eye and skin damaging rays. UV rays are also invisible to the human eye (but visible to certain birds of prey such as raptors

Explanation:

Answer: Energy

Explanation: Light, heat, electricity, sound are examples of energy

Answer:

Explanation:

Pinhole camera is a simple camera. It does not have a lens. The light passes from a hole and an inverted image is formed on the opposite side of the box.

Answer:

Solution

Given:

initial velocity (u)=0m/s (because an object

starts from the rest)

time (t)=3sec

diatance travelled(s)=14m(16-2=14)

acceleration (a)=?

Now,

According to the formula

s=ut+1/2at^2

or,14 =0×3+1/2×a×3^2

or, 14=0+a/2×9

or, 14=9a/2

or, 9a=28

or, a=28/9

or, a=3.1 m/s^2

Therefore, the acceleration of the object is 3.1m/s^2 ans.

Explanation:

The area under a displacement vs time graph is the absement.

Answer:

answer= 73.1256 [tex]i[/tex]

Explanation:

The electric charge linear density is equal to 8.8 x[tex]10^{-9}[/tex]

the length of the string is 3.1m

The magnitude of the electric field at the length of the string equal to 5.2 meters can be calculated with the formula ;

- E = λ / 4πε₀ [ [tex]l[/tex]  / α ( α +

Solution:

E =  8.8 x[tex]10^{-9}[/tex] / 4πε₀ [ 3.1/ 5.2( 5.2 + 3.1) ] [tex]i[/tex]

= 1018.0995 [0.07183] [tex]i[/tex]

=  73.1256 [tex]i[/tex]

Answer:

800km/s

Explanation:

Initial momentum = final momentum

the total momentum is zero, Before the release of the asteroid , but Superman and the asteroid are not moving.

So, according to the Conservation of momentum the total momentum when the astronaut is been thrown will equals to zero . Then we can say

Initial momentum = final momentum

Because the momentum of the Superman immediately the asteroid is been thrown is equal to the momentum of the asteroid

Momentum =(mass ×velocity)

the mass of the asteroid i= 1000M

Given velocity = 800 m/s,

momentum =(1000M)(800 m/s)

= 800,000M m/s.

to get the answer, we need to divide by Superman's mass, M, which gives his recoil velocity of 800,000 m/s.

But we're told to convert to km/ s

We know that 1m/s=0.001km/s

=(800,000M m/s)× (0.001km/s)

=800km/s

Therefore, his recoil speed (in km/s) is 800km/s

Answer:

Explanation:

For acceleration due to gravity g , the expression is

g = GM / R² , where G is gravitational constant M is mass of the earth and R is radius of the earth .

At height h , let the value of it becomes g / 4 , so

g / 4 = GM / ( R + h )²

dividing

4 = [( R+ h)² / R² ]

2 = (R + h) / R

2 = 1 + h / R

h / R = 1

h = R

So at height equal to radius of the earth , acceleration due to gravity becomes 1 /4 of value on the surface of the earth .

Answer:

The meaning of grit in psychology is a positive, non-cognitive trait based on an individual's perseverance of effort combined with the passion for a particular long-term goal or end state.

Answer:

Therefore the laws of physics are the same for the two observers, whoever is standing under the tree observes a vertical movement of free fall.

The person who is running observes a movement parabolic

Explanation:

To answer this question we must establish that as two people have inertial reference systems from which to make their observations, the inertial systems are systems with constant velocity.

Therefore the laws of physics are the same for the two observers, whoever is standing under the tree observes a vertical movement of free fall.

The person who is running observes a movement parabolic composed of the vertical movement and horizontal movement ladies go running, therefore it is a parabolic movement

Traslate

Para responder eta pregunta debemos establecer que as dos personas tiene sistema de referencia inerciales de des donde realizar sus observación, los sistema inerciales son sistema con velocidad constante.

Por lo tanto las leyes de la fisica son la misma para los dos observadores, el que esta parado bajo el árbol observa un movimiento vertical de caída libre.

La persona que va corriendo observa un movimiento compuesto por el movimiento vertical y damas movimiento horizontal ir corriendo, por lo cual es un movimiento parabólico

Derived Quantities

Answer:

These are quantities calculated from two or more measurements

Explanation:

They can't me measured directly.

They can only be computed.

They are calculated in PHYSICAL SCIENCE.

hope it helps.

Answer:

[tex]\phi=1.56\times 10^{-5}\ Wb[/tex]

Explanation:

Given that,

Emf, V = 22 mV

Number of turns in the coil us 519

Rate of change of current is 10 A/s.

We need to find the magnetic flux through each turn of the coil at an instant when the current is 3.70 A.

Let's find the inductance first. So,

[tex]L=\dfrac{\epsilon}{(dI/dt)}\\\\L=\dfrac{0.022}{10}\\\\L=0.0022\ H[/tex]

We have,

[tex]L=\dfrac{N\phi}{I}[/tex], [tex]\phi[/tex] is magnetic flux

[tex]\phi=\dfrac{LI}{N}\\\\\phi=\dfrac{0.0022\times3.7}{519}\\\\\phi=1.56\times 10^{-5}\ Wb[/tex]

So, the magnetic flux is [tex]1.56\times 10^{-5}\ Wb[/tex].

Answer:

D

Explanation:

The answer is D because:

A) Only doctors are allowed to prescribe medications.

B) Rita is not a chef/cook.

C) Rita is not a personal trainer

D) The job of a dietican is to provide reccomendations to their clients in order for them to implement a healthy lifestyle via consuming what is best for them.

Hope this helps :)

Answer:

D.) Making recommendations for healthy eating habits

Explanation: PLATO :)))

Explanation:

The electric force is:

F = k q₁ q₂ / r²

F = (9×10⁹ Nm²/C²) (-1.6×10⁻¹⁹ C) (+1.6×10⁻¹⁹ C) / (6.5×10⁻¹¹ m)²

F = 5.4×10⁻⁸ N

The gravitational force is:

F = G m₁ m₂ / r²

F = (6.67×10⁻¹¹ Nm²/kg²) (9.11×10⁻³¹ kg) (1.67×10⁻²⁷ kg) / (6.5×10⁻¹¹ m)²

F = 2.40×10⁻⁴⁷ N

Answer:

3504 m/s

Explanation:

Let x be the horizontal component of distance

y - vertical component of distance

t-time

ax- horizontal component of acceleration

ay-Vertical component of acceleration

Vx-horizontal component of velocity

Vy-Vertical component of velocity

horizontally: x = V_x ×t + ½×a_x×t²  

plugging the values we get

23500× cos 55º = 1350×cos25.0º × 10.20 + ½×a_x× (10.20)²  

⇒ax = 19.2 m/s²  

Moreover,

V'x = V_x + a_x×t = 1350×cos25.0º + 19.2×10.20= 1419 m/s  

similarly in vertical direction:

y = V_y×t + ½×a_y×t²  

23500×sin55º = 1350×sin25.0º×10.20s + ½×a_y×(10.20)²  

⇒a_y = 258 m/s²  

Also,

V'y = V_y + a_y×t = 1350×sin25.0º + 258×10.20 = 3204 m/s  

Therefore

V = √(V'x² + V'y²) = 3504 m/s  

therefore,  magnitude of final velocity of missile=3504 m/s

THANKS  

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Answer: The frequency increases as the pitch increases, and the amplitude increases as the volume increases

Explanation:

Waves have the property of:

v = f*λ

where v is the speed of the wave (which is almost constant for soundwaves, v = 340 m/s)

f is the frequency of the wave, and λ is the wavelength.

Now, we know that when the pitch of a note increases, also does the frequency of the soundwave (so the wave oscillates faster).

Now, we also want to include the amplitude of the soundwave in this.

The amplitude is related to the volume of the soundwave (actually is related to the energy, and as higher is the energy, more "loud" is the sound).

As the high pitch part is usually "louder", we can assume that we have an amplitude increase.

Then the answer would be:

"The frequency increases as the pitch increases, and the amplitude increases as the volume increases"

Answer:

5 W

Explanation:

The formula of the power is:

● P = W/t

W is the work and t is the time needed to do it(in seconds)

Let's calculate first the work that the force exerced:

W = Vector F . Vector d

D is the distance ( here 400 cm wich is 4 m)

Make a representation to see how are the vectors F and V.(picture below)

The vector F and d are colinear since Den is pushing the desk on the ground.

● W = 4 × 10 = 40 J

J is Joule

■■■■■■■■■■■■■■■■■■■■■■■■■■

● P = W / t

● P = 40/ 8

● P = 5 W

The power output of the force of 10N for 8 seconds to move the desk is 5 watts. Thus, the correct option is B.

Power is the amount of energy which is transferred or converted per unit time. In the SI system of Units, the unit of power is the watt, which is equal to one joule per second time.

We Know, P = W/t

where, P = Power,

W = Work done,

t = Time taken

P = F × s/t

where, F = Force applied,

s = distance travelled,

t = time taken

Here, F = 10N

s = 400cm = 4m

t = 8 sec

Substitute their values into the expression,

P = 10 × 4/8

P = 10 × 1/2

P = 5 Watt

So, the power output will be 5 watts.

Therefore, the correct option is B.

Learn more about Power here:

https://brainly.com/question/287674

#SPJ6

this process is called parellelogram method of resolving vectors.

Answer:

velocity

Explanation:

Unbalanced forces on an object cause it to accelerate.  Acceleration is a change in velocity over time.

Answer:

a

Explanation:

none