What is the force on the book in the figure below ? If the book moves, in which direction will it move ?

Pleaseeee help !!!!!!!

Answer:

499.73 m

Explanation:

We'll begin by calculating the change in the temperature. This can be obtained as follow:

Initial temperature (T₁) = 25 °C

Final temperature (T₂) = –20° C

Change in temperature (ΔT) =?

ΔT = T₂ – T₁

ΔT = –20 – 25

ΔT = –45 °C

Finally, we shall determine the length on a cold day at –20° C. This can be obtained as follow:

Length at 25°C (L₁) = 500 m

Coefficient of linear expansion (α) = 12×10¯⁶ /°C

Change in temperature (ΔT) = –45 °C

Length at –20 °C (L₂) =?

α = L₂ – L₁ / L₁ΔT

12×10¯⁶ = L₂ – 500 / (500 × –45)

12×10¯⁶ = L₂ – 500 / –22500

Cross multiply

L₂ – 500 = 12×10¯⁶ × –22500

L₂ – 500 = –0.27

Collect like terms

L₂ = –0.27 + 500

L₂ = 499.73 m

Therefore, the length on a cold day at –20° C is 499.73 m.

Answer:

t = 2.7 seconds

Explanation:

Given that,

Initial speed, u = 3.8 m/s

Final speed, v = 4.2 m/s

Acceleration of Michael, a = 0.15 m/s²

(a) Let t is the time taken by him to catch Robert. It can be calculated as follows :

[tex]a=\dfrac{v-u}{t}\\\\t=\dfrac{v-u}{a}\\\\t=\dfrac{4.2-3.8}{0.15}\\\\t=2.7\ s[/tex]

So, the time taken is 2.7 seconds.

Answer:

2) zero acceleration

Explanation:

Motion can be defined as a change in the location (position) of a physical object or body with respect to a reference point.

This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.

Mathematically, the motion of an object is described in terms of time, distance, speed, velocity, position, displacement, acceleration, etc.

In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.

Generally, an object is said to be in equilibrium when neither the energy possessed by the object not state of motion changes with respect to time. Thus, the vector sum of all the forces acting upon an object that's in equilibrium is zero.

In conclusion, an essential characteristic of an object in equilibrium is zero (0) acceleration because there's no change in its velocity with respect to time.

Expla

pV/T=const goodluke

Answer:

here it is...

Explanation:

The friction between the two surfaces is because of the interlocking of the irregularities of the two surfaces. During sliding, contact points do not get enough time to get interlocked properly. Therefore, less friction. ... This explains why sliding friction is less than static friction.

Answer:

1. These lines are addressed to Duke.

2. These lines show that Shylock is not willing to forgive the debt a merchant owes him, nor is he willing to justify why he demands that debt be paid, even if it seems cruel.

3. He swore by the Holy Sabbath, which is a holy day for him, who is a Jew. He swore he would get the debt money or a piece of the debtor's flesh.

Explanation:

The lines shown in the question above refer to "The Merchant of Venice" written by Shakespeare. In this story we are introduced to Antonio, a commercial who is very prejudiced against Jews, but when he needs money, he borrows from another merchant, Shylock, who is Jewish. Shylock agrees to lend money to Antonio, but determines the date that this money must be returned, in addition, Shylock states that he will lend the money if Antonio agrees that if this money is not paid by the specified date, Antonio will have to pay with half a kilo of flesh from his own body. Antonio agrees, but doesn't pay the money so Shylock goes after the flesh of Antonio's body and Duke tries to intervene because he thinks this is too cruel. At this point, Shylock speaks the lines shown in the question above, showing that he is not willing to change his mind.

Answer:

Explanation:

(a)

In event A , one has to walk along diameter of the field from X to Y.

In this event , walk is along a straight line , both displacement and distance covered will be same.

Distance = displacement = 1 km.

option ii is correct .

(b )

radius of circular track r = 0.5 km

length of track = circumference = 2π r

= 2 x 3.14 x .5 = 3.14 km

Length of running in event B is 15.7 km

No of rounds = 15.7 / 3.14 = 5

option iii is correct .

( c )

speed = length of race / time

time = length of race / speed

= 15. 7 km / 3.14 km /h

= 5 hours .

option iv is correct option.

(d)

In event C , length of race is 25.12 km

speed = length of race / time taken

= 25.12 km  / 4 hour

= 6.28 km/h .

Option i is correct.

Answer:

(a) (ii)

(b) (iv)

(c) (i)

(d) (i)

Explanation:

diameter, XY = 1 km

Event A- Fast walking along the diameter of the field.

Event B- A 15.7 km running race along the circular track.

Event C- A 25.12 km cycling race along the circular track.

(a) When athletes walked from X to Y , the distance is equal to the displacement which is equal to the diameter = 1 km.  

Option (ii).

(b) distance = 15.7 km

distance traveled by one round = 3.14 x 1 = 3.14 km

So, the number of round complete in B = 1.57/3.14 = 0.5

option (iv).

(c)If Pihu ran at an average speed of 3.14 km/h during Event B, then she would finish the race in

time, t = 1.57/3.14 = 0.5 hours

option (i)

(d) What should the average speed of cyclist Yousef be, so that he can complete Event C in 4hours?

Distance = 25.12 km

time , t = 4 hours

Speed = 25.12 / 4 = 6.28 km/h

Option (i)

Answer:

Explanation:

The negative only matters reallly if you are dealing with a 2d system. I could even define down as positive and up as negative. However, usually you are taught that down is negative. It really doesn't matter because a force is a force. It is only given a direction relative to another force or vector direction.

Answer:

D. more mass is concentrated.

Explanation:

Gravity is considered to be a universal force of attraction which acts between all objects that has both mass, energy and occupy space. Therefore, it acts in such a way as to bring objects together.

Additionally, the gravity of earth makes it possible for all physical objects to possess weight.

Newton's law of universal gravitation states that the force of attraction (gravity) acting between the Earth and all physical objects is directly proportional to the Earth's mass, directly proportional to the physical object's mass and inversely proportional to the square of the distance separating the Earth's center and that physical object.

Center of gravity can be defined as the specific point where all of the weight of an object is concentrated.

Generally, all the objects found around the world all have a center of gravity.

Additionally, when an object is balanced so that a displacement lowers its center of gravity, the object is said to be in stable equilibrium.

The centre of gravity of a physical object is usually located where more mass is concentrated in the physical object or body.

However, the location of the centre of gravity is subject to change and as such doesn't always remain the same.

Answer:

B

Explanation:

Stress-strain diagram with 4 materials graphed. The graph with maximum yield strength is B.

Stress is defined as the force applied per unit area of cross-section. It is denoted by Sigma(σ). Its's unit is same as the pressure i.e. N/m².

Considering the stress-strain diagram shown here. Assumed all four material samples denoted as (A-D) were originally the same size and shape.

When a body is stretched by a tensile force, it stretches more and more until it reaches its elastic limit. There comes a point where the body no longer stretches. The change in stress is very less and the stress is greater at the yield point. The strength required up to the yield point is called as the yield strength. The body breaks while forming the neck of the bottle. This strength of any material is known as ultimate stress at break or ultimate tensile strength.

So, the material with the highest yield strength is B.

Thus, the correct option is B.

Learn more about Stress.

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Magnetic force between the north poles of two magnets is REPULSIVE

Answer:Repulsion or attraction

Explanation:The angle between the compass needle   and geographic north is called the MAGNETIC DECLINATION.(see earth:the magnetic field of the earth ). The repulsion or attraction between two magnetic dipoles can be viewed as the interaction of one dipole with the magnetic field produced by other dipole.

Answer:

If 2 objects have the same mass, then which object has a larger volume will have a smaller density

Explanation:

Because density is the object's mass divided by volume

Answer:

A. So that you can see if the answer to a problem makes physical sense.

Explanation:

Science can be defined as a branch of intellectual and practical study which systematically observe a body of fact in relation to the structure and behavior of non-living and living organisms (animals, plants and humans) in the natural world through experiments.

An experiment can be defined as an investigation which typically involves the process of manipulating an independent variable (the cause) in order to be able to determine or measure the dependent variable (the effect).

This ultimately implies that, an experiment can be used by scientists to show or demonstrate how a condition causes or gives rise to another i.e cause and effect, influence, behavior, etc in a sample.

Measurements refers to the process which typically involves the process of identifying and determining the dimensions of a physical object. The dimensions include important parameters such as width, height, length, area, volume, circumference etc.

In Science, making rough estimates of physical quantities is useful so that you can see if the answer to a problem makes physical sense.

For example, you could make a rough estimate of a storage tank and deductively determine whether or not it's in tandem with its physical size in reality.

Answer:

a ) Its wavelength decreases

Explanation:

When a ray enters into air from glass slab its wavelength decreases.

Group of answer choices.

A. Energy is absorbed in the reaction.

B. Energy is released in the reaction.

C. There is no transfer of energy in the reaction.

D. Energy is lost in the reaction.

Answer:

B. Energy is released in the reaction.

Explanation:

A chemical reaction can be defined as a chemical process which typically involves the transformation or rearrangement of the atomic, ionic or molecular structure of an element through the breakdown and formation of chemical bonds to produce a new compound or substance.

Basically, there are two (2) main types of chemical reaction and these include;

I. Endothermic reaction: it's a chemical reaction in which heat is absorbed

II. Exothermic reaction: it's a chemical reaction in which heat is liberated into the environment.

In Chemistry, all chemical equation must follow or be in accordance with the Law of Conservation of Mass, which states that mass can neither be created nor destroyed by either a physical transformation or a chemical reaction but transformed from one form to another in an isolated (closed) system.

Generally, energy is released in a chemical reaction when the energy of the products is less than the energy of the reactants and it is referred to as an exothermic reaction.

However, when the energy of the products is greater than the energy of the reactants, energy is absorbed and it is referred to as an endothermic reaction.

Answer:

(i) The particle has a period of 0.3 seconds.

(ii) The angular velocity of the particle is a20.944 radians per second.

(iii) The linear velocity of the particle is 1.047 meters per second.

(iv) The linear acceleration of the particle is 21.933 meters per square second.

Explanation:

Statement is incomplete and have mistakes, complete and correct form is presented below:

A particle makes 800 revolutions in 4 minutes of a circle with a radius of 5 centimeters. Find (i) its period, (ii) its angular velocity, (iii) its linear velocity and (iv) its acceleration.

(i) The period of the particle ([tex]T[/tex]), in seconds, is the time taken to make a complete revolution:

[tex]T = \frac{4\,min \times \frac{60\,s}{1\,min} }{800\,rev}[/tex]

[tex]T = 0.3\,s[/tex]

The particle has a period of 0.3 seconds.

(ii) The angular velocity ([tex]\omega[/tex]), in radians per second, is determined by the following formula:

[tex]\omega = \frac{2\pi}{T}[/tex] (1)

[tex]\omega = \frac{2\pi}{0.3\,s}[/tex]

[tex]\omega \approx 20.944\,\frac{rad}{s}[/tex]

The angular velocity of the particle is a20.944 radians per second.

(iii) The linear velocity ([tex]v[/tex]), in meters per second, is calculated by the following formula:

[tex]v = R\cdot \omega[/tex] (2)

Where [tex]R[/tex] is the radius of the circle, in meters.

If we know that [tex]R = 0.05\,m[/tex] and [tex]\omega \approx 20.944\,\frac{rad}{s}[/tex], then the linear velocity of the particle is:

[tex]v = (0.05\,m)\cdot \left(20.944\,\frac{rad}{s} \right)[/tex]

[tex]v = 1.047\,\frac{m}{s}[/tex]

The linear velocity of the particle is 1.047 meters per second.

(iv) Since angular velocity is constant, linear acceleration of the particle ([tex]a[/tex]), in meters per square second, is entirely radial. Acceleration can be found by means of this expression:

[tex]a = \omega^{2}\cdot R[/tex] (3)

If we know that [tex]R = 0.05\,m[/tex] and [tex]\omega \approx 20.944\,\frac{rad}{s}[/tex], then the linear acceleration of the particle is:

[tex]a = \left(20.944\,\frac{rad}{s} \right)^{2}\cdot (0.05\,m)[/tex]

[tex]a = 21.933\,\frac{m}{s^{2}}[/tex]

The linear acceleration of the particle is 21.933 meters per square second.

Answer:

117.72 N

Explanation:

The given parameters are;

The mass m₁ = 2.0 × 10³ kg

The mass m₂ = 4.4 × 10² kg

The mass of the man, m₃ = 6.0 × 10 kg

The condition of the interaction of the surfaces = Frictionless surfaces

The

The tension in the string = The downward force = The weight of (m₂ + m₃) = (m₂ + m₃) × g

Let a represent the acceleration of the connected masses due to the weight of m₂, and m₃, we have;

(m₁ + m₂ + m₃) × a = (m₂ + m₃) × g

∴ a = (m₂ + m₃) × g/(m₁ + m₂ + m₃)

Which gives;

a = (4.4 × 10²+ 6.0 × 10) × 9.81/(2.0 × 10³+ 4.4 × 10²+ 6.0 × 10) = 1.962

The downward acceleration, a = 1.962 m/s²

The apparent weight of the man = The mass of the man, m₃ × The acceleration, a

∴ The apparent weight of the man = 6.0×10 kg ×1.962 m/s² = 117.72 N

Answer:

90 degree

Explanation:

Electric field line is vertical to the electric field line.

The angle between the field line and the equipotential where an electric field line crosses an equipotential surface is 90°

This is a region of space around a charged particle, or between two voltages.

The angle between Electric field crosses an equi-potential surface is always 90 degrees. When the potential becomes constant,the negative potential gradient also becomes zero, hence necessitating the need for Electric field to be always normal with surface.

Therefore, the angle between electric field and equi-potential surface is 90 degrees.

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Answer:

The distance of car form the mirror is 330 cm.

Explanation:

height of object, h = 140 cm

height of image, h' = 14 cm

radius of curvature, R = 60 cm

focal length, f = R/2 = + 30 cm

Let the distance of image is v and the distance of object is u.

[tex]\frac{h'}{h}\frac{v}{u}\\\\\frac{14}{140} =\frac{v}{u}\\\\v =\frac{u}{10}[/tex]

Use the formula of focal length

[tex]\frac{1}{f}=\frac{1}{v}+\frac{1}{u}\\\\\frac{1}{30}=\frac{10}{u}+\frac{1}{u}\\\\\frac{1}{30}=\frac{11}{u}\\\\u = 330 cm[/tex]

Answer:

The work done is 12 MJ.

Explanation:

The engine of a car exerts a constant traction force of F=4000N . Assume that the car is moving at a constant speed of 36 km/hr. In five minutes, what is the work done by the engine's traction?

Force, F = 4000 N

speed, v = 36 km/h = 10 m/s

time , t = 5 minutes = 5 x 60 = 300  s

Work done is given by

W =  force x distance

W = 4000 x 10 x 300 J = 12 x 10^6 J = 12 MJ

Answer:

q = 2.65 10⁻⁶ C

Explanation:

For this exercise we use Coulomb's law

        F =[tex]k \frac{q_1q_2}{r^2}[/tex]

In this case they indicate that the load is of equal magnitude

       q₁ = q₂ = q

the force is attractive because the signs of the charges are opposite

       F = [tex]k \ \frac{q^2}{r^2}[/tex]

       q = [tex]\sqrt{\frac{F \ r^2}{k} }[/tex]

we calculate

        q = [tex]\sqrt{\frac{0.7 \ 0.3^2 }{9 \ 10^9} }[/tex]

        q = [tex]\sqrt{7 \ 10^{-12} }[/tex]Ra 7 10-12

        q = 2.65 10⁻⁶ C

Answer:

hey !! here is a short and sweet answer to your question

=quality of life is directly determined by health ,education ,and life expectacy

=health Is a type of thing that gives employment to the person working in firm

hope u understand

Explanation:

Answer:

physical measurement comprises the measurement of objects, things, etc. and is concerned with the measurement of height, weight, length, size, volume etc.

Answer:

A

Explanation:

low credit score means its more risky to lend someone money

Answer:

Gamma rays

Gamma rays have the highest energies, the shortest wavelengths, and the highest frequencies.