A 75-N box rests on a perfectly smooth horizontal surface. The minimum force need to start the box moving
is
A) 7.5 N. B) 75 N.
C) 750 N. D) any horizontal force greater than zero.

Answer: [tex]2666.67 \text{ (or in 2 sigfigs, }2.7\times10^{3})[/tex]

Explanation: [tex]1\text{ }\dfrac{\text{N}}{\text{m}^2} = 1 \text{ Pa}\\\\P=\dfrac{F}{A}\\\\P=\dfrac{800\text{ N}}{0.3\text{ m}^2} = 2666.\overline6 \text{ N/m}^2 \approx 2666.67 \text{ Pa} \approx 2.7 \text{ kPa}[/tex]

Don't know if you need to convert to other units but typically in physics it's left as N/m^2 or Pa.

As the larger cross-sectional area results in less stress force therefore, for the same force , stress is less in large cross -section and it streches less

According to Hooke's rule, stress and strain are directly inversely related, meaning that as stress rises, strain rises as well. There is no need that the connection between strain and stress be linear. It is valid when the deformation is caused by a relatively tiny bulk stress.

Stress=K×strain

The elastic modulus is the proportionality constant characterizing the connection between stress and strain.

Stress=Elastic modulus×Strain

The term "bulk modulus" refers to the elastic modulus for bulk stress. The ability of the material to endure changes in volume under pressure from all sides may be expressed numerically as the bulk modulus. It describes the elastic characteristics of solids and fluids under pressure on all surfaces.

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The speed of the ball during centripetal motion is 4.75 m/s.

We need to know about centripetal force to solve this problem. When an object moves in a circular motion, the object is experiencing centripetal force. The magnitude of centripetal force is

Fc = m . v²/R

where Fc is the centripetal force, m is mass, v is velocity and R is the radius.

From the question, we know that

m = 0.11 kg

F = 4 N

R = 0.62 m

The tension in the string is equal to centripetal force

T = Fc

4 = m . v²/R

4 = 0.11 . v² / 0.62

v² = 22.55

v = 4.75 m/s

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The mass of a blow dart that experiences a blowing force of 0.20 Newtons and travels the length of the 1.2 meter barrel in 0.04 seconds is 0.26 g

a = v / t

v = d / t

a = Acceleration

v = Velocity

d = Distance

t = Time

d = 1.2 m

t = 0.04 s

v = 1.2 / 0.04

v = 30 m / s

a = 30 / 0.04

a = 750 m / s²

According to Newton's second law of motion,

F = m a

F = Force

m = Mass

F = 0.2 N

m = F / a

m = 0.2 / 750

m = 2.6 * [tex]10^{-4}[/tex] kg

m = 0.26 g

Therefore, the mass of a blow dart is 0.26 g

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Answer:

F = 20 N

Explanation:

Given:

m = 0.12 kg

H = 2.3 m

S = 0.067 m

g = 9.8 m/s²

____________

F - ?

1)

Potential energy over grass:

Wp = m*g*H = 0.12*9.8*2.3 ≈ 2.7 J

2)

Work against the friction force of the grass:

A = F₁*S

3)

According to the law of conservation of energy:

A = Wp

F₁*S = Wp

F₁ = Wp / S = 2.7 / 0.067 ≈ 40 N

4)

Average grass resistance strength:

F = F₁ / 2 = 40 / 2 = 20 N

If the coefficient of kinetic friction between two sliding surfaces is μ and the normal force between them is N, then the kinetic friction between them is given by μ = F/N . Therefore N= 800.

Given

kinetic friction μ = 0.3

and kinetic friction μ = F/N

N =  normal force

where F = frictional force

F = 240 n

N = F/μ

= 240 n/0.3

N = 800 n

There are two types of friction kinetic friction, also known as dynamical friction, and static friction. A force acting in opposition to the direction of a moving body on the surface is felt. The two materials' coefficient of kinetic friction will determine how much force is applied.  Kinetic friction occurs whenever two surfaces slide past one another. The application of brakes to tyres, the movement of an object across the ground, such as a box, or the rubbing of sandpaper all cause kinetic friction. The coefficient of friction, which measures the relationship between the frictional force and the normal force, provides a good description of friction. It obstructs the motion of several different items.

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If Leandra is working with a machine that uses 10,000 watts of power in 2 hours, then the amount of work done by the machine would be  72000000 Joules.

The total amount of energy transferred when a force is applied to move an object through some distance.

The work done is the multiplication of applied force with the displacement.

As given in the problem  Leandra is working with a machine that uses 10,000 Watts of power in 2 hours,

Power = work done / time

10000 = work done /3600*2

Work done = 72000000 Joules

Thus, the work done by Leandra would be 72000000 Joules.

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[tex]\huge\underline\mathcal{Answer \: - }[/tex]

velocity is a vector quantity that tells us about the speed as well as direction of an object.

Thus , the best description of velocity will be the one which tells us the speed as well as direction of the rolling pen.

therefore ,

the last option 4 cm/s west is correct!

hope helpful ;-;

a) The time taken is 4.44 s

b) The force that keeps it moving is 15188 N

c) The centripetal force is responsible for the motion in the circular path.

d) The coefficient of the friction is 1.03

The centripetal force is the force that keep the object moving in a circular path. In this case, we need to find the how long does it take the car to do a lap around the track.

a) The time that is taken is the radio of the distance to the speed of the object. Thus the time that is taken =  200 m/45 m/s = 4.44 s

b) The net force that acts on the car as it is negotiating the circular path is given as; mv^2/r = 1500 * (45)^2/200

= 15188 N

c) The centripetal force keeps the car on the circular path

d) The coefficient of static friction is; 15188 N/1500 kg * 9.8 m/s^2

= 1.033

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The combined velocity of the car and the chair is 1.5 m/s.

By the use of the law of the conservation of linear momentum we know that the total momentum before collision is equal to the sum of the final momentum after collision.

We have to first obtain the momentum of the system before and after the collision has occurred as we see below;

Then we have;

Momentum before collision = 2 Kg * 60 m/s = 120 Kgm/s

Momentum after Collison = 80v Kgm/s

Momentum = mv

m = mass of the object

v = velocity of the object

Using the principle of the conservation of momentum;

120 = 90v

v = 120/80

v = 1.5 m/s

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Therefore, the electric charge will travel in a circle around a fixed point. Positive charges move in a counterclockwise manner when the magnetic field is pointing into the page, whereas negative charges move in a clockwise direction (apply the right hand rule).

Perpendicular to the direction of motion is the direction of the force caused by a magnetic field.

According to the right hand rule, you should point your right thumb toward the direction of the velocity (v), your index finger toward the direction of the magnetic field (B), and your middle finger toward the direction of the magnetic force that results from that.

Right hand rule #1 governs the direction of the magnetic force on a moving charge, which is perpendicular to the plane formed by v and B. (RHR-1)

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The substance that requires the greatest amount of energy to melt is ice.

The latent heat of fusion refers to the energy that is required to melt 1 Kg of a substance. We must note that this heat goes into the breaking of the internal bonds of the material. Thus, the nature of the internal bonds in the materials are important when we are dealing with the latent heat of fusion.

We can see that the particles of ice are held together by the strong hydrogen bonds. As such, we can see that ice has the highest latent heat of fusion.

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The gas's internal energy rises by 250 J when the value is positive. So, the increase in temperature of the gas is 250 J.

Any device addressing the relationship between heat and work must be designed with a working knowledge of thermodynamics. This method ignores actions that take place at the molecular level in favor of considering a particular amount of matter.

In macroscopic thermodynamics, the effects are based on observable, quantifiable quantities, and the attributes of the system are given to the system as a whole.

Work cannot "store" energy like the aforementioned forms can. It is merely a momentary manifestation process of energy transmission. Heat cannot transport energy either; it is merely a temporary manifestation process. Therefore, other types of energies in transition include heat and work.

by setting a limit, identifies the subject of the manifestation analysis. Either "a distinct collection of substance" or "a region in space" must be handled consistently.

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In the case of falling, the time will double then the height will increase  by a factor of 4 times.

In this problem, we are dealing with free-falling and distance, where distance is The physical quantity that can be defined by how the object or body is seen far away, whereas displacement and  Distance both are different physical meanings but have the same standard units and whereas a free falling object is an object that's falling beneath the sole impact of gravity. Any object that's being acted upon as it were by the force of gravity is said to be in a state of free fall.

Since we are given that the falling time is doubled,  since  the formula for the distance by the equation of motion is

s=1/2gt²

where g is the acceleration due to gravity and t  is the time, so if the time is increased by 2 times, then the distance increase by the value of 4 times as distance is  directly proportional to the square of the falling time.

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The speed of the protons v is 1.089[tex]e^{8}[/tex] m/s.

Every atom has a proton, a subatomic particle, in its nucleus. The particle has an electrical charge that is opposite to the electrons and is positive.

To establish a potential difference, a unit of positive electric charge must be transported from one location to another.

Here we are given a potential difference as 62MV= 62[tex]e^{6}[/tex]V

Now, as per classical definition, equation P.E. and the K.E.

So we have,

qV = 1/2[tex]\frac{m}{s^{2} }[/tex]

V is the potential difference and v is the velocity.

v = [tex]\sqrt\frac{2qV}{m}[/tex]

By substituting the values we get,

v = 1.089[tex]e^{8}[/tex] m/s

The speed of the protons v is 1.089[tex]e^{8}[/tex] m/s.

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A patient's tumor is being treated with proton-beam therapy. The protons are accelerated through a potential difference of 62 MV. What is the speed of the protons? (Note: The speed is high enough that, in principle, we should use a relativistic calculation something you'll learn about in Chapter 27 but for this problem, you should use the formulas you are already familiar with.)

The velocity of the car just before breaking 35.9 m/s

Braking distance, s = 92.0 m

Deacceleration = 7 m/s²

Speed of the car when stopped, =0

Let the speed of the car  just before braking, =0

Using the equation of motion ²=²+2as

² = ² - 2as

² = 0² - 2(-7)(92.0)

² = 1288

≈ 35.9 m/s ← speed of the car just before breaking

Acceleration can be defined as a vector quantity that determines the rate at which an object changes its velocity. An object continues to accelerate as it changes its speed over and over again.

Acceleration has nothing to do  with changing the target's movement speed. If an object does not change its speed, then the object is not accelerating. The data on the right represents an object moving north. The speed of the target changes over  time. In fact, the speed changes by a constant amount - ie. 10 m/s - every second. When the speed of an object changes, the object is said to be in accelerated motion or  acceleration.

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The other force has magnitude of 2.41 N and direction opposite to that of force 3.71 N parallel to x axis

Let the other force=P

work done=total force*displacement

16.7=(P+3.71)*11

P+3.92=1.51

P=-2.41

Newton is the abbreviation for the SI unit of absolute force known as newton (N). It is described as the amount of force required to accelerate a kilogram of mass by one meter per second. In the foot-pound-second (English, or customary) system, one newton is equivalent to around 0.2248 pounds of force or 100,000 dynes in the centimeter-gram-second (CGS) system.

The newton was given its name in honor of Sir Isaac Newton, whose second rule of motion outlines the modifications that a force may cause in a body's motion.

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The volume of the cylinder is 1.57 x 10⁻³ m³.

V = πr²h

V = π(5cm)²(20cm)(1m/100cm)³

V = 1.57 x 10⁻³ m³

The mass of the cylinder is 12.25 kg.

ρ =  m/v

m = ρv

m = (7800 kg/m³)(1.57 x 10⁻³ m³)

m = 12.25 kg

Add the eyepiece's power, typically 10X, to the objective's (4x) power to get the overall magnification. Total magnification for 4x lens is 40x and 10x is 400x.

Make sure the 4X scanning objective is locked into position and the stage is completely down before viewing a slide through the microscope.

Set the slide over the aperture that you want to see, then carefully place the stage clips on top of the slide to secure it in place.

Start with the 4X objective, keep both eyes open while looking through the eyepiece (if necessary, cover one with your palm), and gradually raise the stage using the coarse adjustment knob until the image is clear. The coarse adjustment knob will only need to be used once during the operation. You will be utilizing parfocal microscopes, which means that the image. Things appear 40 times bigger than they are using a 40x objective. Comparing objective magnification is relative. The capacity of a microscope to create an image of an object at a scale bigger (or even smaller) than its real size is known as magnification.

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If you have a tire blowout when driving on the highway, you should not use your brakes until the vehicle has nearly rolled to a stop.

If you have a tire blowout when driving on the highway, you should not use your brakes until the vehicle has nearly rolled to a stop because at high speed the deviation is more.

Rolling is a type of motion that combines rotation and translation of that object with respect to a surface, such that, if ideal conditions exist, the two are in contact with each other without sliding. Rolling where there is no sliding is referred to as pure rolling.

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If a bird flying 3.45 m / s directly north feels a window directly east and accelerates 0.558 m / s², then its velocity after 5.25 seconds would be

There are three equations of motion given by  Newton,

v = u + at

S = ut + 1/2×a×t²

v² - u² = 2×a×s

As given in the problem If a bird flying 3.45 m / s directly north feels a window directly east and accelerates 0.558 m / s²,

By using the first equation of motion,

v = u + a × t

v = 3.45 + 0.558 × 5.25

v =  6.537 m / s

Thus, its velocity after 5.25 seconds would be 6.537 m / s

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Answer:

  about 4.53 m/s 40.3° east of north

Explanation:

You want the velocity of a bird flying 3.45 m/s north after being accelerated by a wind at 0.558 m/s² directly east for 5.25 seconds.

The attached table shows the result of the acceleration. The change in "x" velocity is the product of the acceleration and time. The y-velocity is unaffected by the easterly acceleration.

The magnitude of the final velocity is the root of the sum of the squares of its components:

  Vf = √(2.9295² +3.45²) ≈ 4.5226 . . . . m/s

The direction of the final velocity is ...

  arctan(3.45/2.9295) ≈ 49.7° . . . . . CCW from east

The magnitude of the bird's final velocity is about 4.53 m/s. Its direction is about 40.3° east of north, or 49.7° north of east. The components of the velocity are about 2.93 m/s east and 3.45 m/s north.

__

Additional comment

The second attachment shows the bird's direction as a "bearing" angle, conventionally measured clockwise from north. The answer above gives the complementary angle, measured CCW from east.

Problem values are given to 3 significant figures, so we have rounded results to that precision.

From the calculation, the activity of the isotope is 70.7 Bq.

We define the term half life as the amount of a radioactive isotope that is left after a given time. It is in fact the time that it takes for only half of the amount of the radioactive isotopes that is in a sample to remain.

Recall that if a substance is radioactive, this implies that the sample is capable of spontaneous disintegration. The amount of the sample that is present tends to diminish in the system as time increases.

Give the fact that;

Ao = initial activity = 100Bq

A = activity after time t = ??

Time taken = 5 minutes

Half life of the isotope = 10 minutes

Now we know that;

A/Ao = (1/2)^t/t1/2

A/100 = (1/2)^5/10

A/100 =  (1/2)^1/2

A =  (1/2)^1/2 * 100

A = 70.7 Bq

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If we have an ideal spring and attach a mass of 3.75 kg to it such that the spring extends from 12 cm to 13.40 cm, then its spring constant is 2678.57 N/m

When a force applied to a spring, then according to the Hooke's Law:

F = - k. x

Where:

F = applied force

k = spring constant

x = change in spring's length

The minus sign indicates that the displacement and the restoring force is in the opposite direction.

The given parameters:

x1 = 12 cm

x2 = 13.4 cm

Hence,

x = x2 - x1 = 13.4 - 12 = 1.4 cm = 1.4 x 10⁻² m

F = 3.75 . 10 = 37.5 N

Then,

k = F/x = 37.5 / (1.4 x 10⁻² ) = 2678.57 N/m

Complete question:

An ideal spring of negligible mass is 12.00 cm long when nothing is attached to it. when you hang a 3.75 kg object from it, you measure its length to be 13.40 cm. What is the spring constant?

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tan0=1.95 and tan0=0.605 are two solutions. 0 = 63 and theta 0 = 31 are the corresponding (first quadrant) angles.

The elevation angle is the angle between the horizontal line of sight and the object when standing and looking at something. The angle of depression is the angle between the horizontal line of sight and the object if the person is standing and looking down at the object. The rise or rise of something is called elevation. Mountains have an elevation based on their height, and your mood rises the happier you are. Elevation is a noun that describes the height of something above a surface or ground line. It is also a term of measurement for things like temperatures or degrees.

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Alcohol abuse can lead to various health risks including brain damage, heart diseases, stroke etc. But studies yet not proved any connection of alcohol use with lung cancer.

Alcohols are organic compounds with OH groups. They are used in beverages as sprits which causes, neurodegeneration and nerve injury. The use of alcohol and further adverse affects is called alcohol abuse.

Alcohol abuse leads to severe damages to almost all parts of the body from brain to digestive system. Alcoholic products interfere with the nerve functions and suppress the excitatory nerve pathway activity causing brain damage and strokes.

Alcohol abuse further causes high blood pressure and damage to the heart valves . However, is is not reported that alcoholic use cause lung cancer. It is mainly caused by smoking. Thus option a is correct.

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We wouldn't be able to observe the black hole if the accretion disc in it didn't create any light. Due to the black hole's intense gravitational pull, these particles spin at incredibly high speeds, producing an accretion disc and radiation in the process.

Therefore, there is no light when the accretion disc is absent.

Please refer to the solution for this step.

So, option an is the proper response. All other possibilities are false.

Please refer to the solution for this step.

A is the right response in this case.

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Answer:

m v1 = M V + m v2              conservation of momentum

V = m (v1 - v2) / M

V = .022 (240 - 125) / 1.7 = 1.49 m/s

In physics, a system is said to be in equilibrium when neither its internal energy state nor its state of motion tend to vary over time. If all of the forces operating on a single particle are vector summated to zero, equilibrium occurs.

In physics, tension is the pulling force that is conveyed axially by a string, cable, chain, or other similar one-dimensional continuous item, or by either end of a rod, truss member, or other similar three-dimensional object.

Equilibrium refers to the state of a system when neither its internal energy state or state of motion tend to change over time. Equilibrium for a single particle occurs when the vector sum of all force acting on the particle is zero.

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reaction

Newtons third law states that for every action there is an equal but opposite reaction

and for that object (rocket, missile, jet,) as the engine is ignited the force of the burning fuel pushes backward while the rocket moves forward so the rate at which the fuel burns is equal to the rate at which the object moves forward

the force at which the burning fuel pushes backward is equal but opposite to the rate at which the object moves forward

Answer:

  36 years

Explanation:

Given the equation of Kepler's third law as T² = a³, you want to know the period of an asteroid that has an orbital radius of 11 au.

Solving the given equation for t, we find ...

  T = a^(3/2) . . . . . . take the 1/2 power

Then for a=11, the period in years is ...

  T = 11^(3/2) ≈ 36.48

The period of the asteroid is about 36 years.