1. A stone of mass 0.8 kg is attached to a 0.9 m long string. The string will break if the tension exceeds 60 N. The stone is whirled in a horizontal circle on a frictionless tabletop while the other end of the string remains fixed. What is the maximum speed the stone can attain without breaking the string?

A. 8.22 m/s
B. 7.30 m/s
C. 9.34 m/s
D. 7.76 m/s

2. A highway curve with radius 900 ft is banked so that a car traveling at 55 mph will not skid sideways even in the absence of friction. At what angle should the curve be banked to prevent skidding?

A. 14.6°
B. 18.9°
C. 10.9°
D. 12.7°

3. A button will remain on a horizontal platform rotating at 40 rev/min as long as it is no more than 0.15 m from the axis. How far from the axis can the button be placed without slipping if the platform rotates at 60 rev/min?

A. 0.365 m
B. 0.338 m
C. 0.225 m
D. 0.294 m

4. What is the tension in a cord 10 m long if a mass of 5 kg is attached to it and is being spun around in a circle at a speed of 8 m/s?

A. 67 N
B. 28 N
C. 32 N
D. 50 N

5. A 0.5 kg mass attached to a string 2 m long is whirled around in a horizontal circle at a speed of 5 m/s. What is the centripetal acceleration of the mass?

A. 11.3 m/s2
B. 12.5 m/s2
C. 5.9 m/s2
D. 10.2 m/s2

6. Find the maximum speed with which a car can round a curve that has a radius of 80 m without slipping if the road is unbanked and the coefficient of friction between the road and the tires is 0.81.

A. 44.3 m/s
B. 20.8 m/s
C. 25.2 m/s
D. 30.6 m/s

Answer:82. Since you have a distance and a force, then the easiest principle to use is energy, i.e. work.

The work done by friction is F * d. This work cancels out the kinetic energy of the stone (1/2)mv^2

Fd = (1/2)mv^2

F = (1/2)mv^2/d.

Plug in m = 20 kg, v = 3 m/sec, d = 40 m.

83. With more mass, the kinetic energy is higher now. The work needed is higher. W = F * d and F is the same.

Explanation:Hope I helped :)

Answer:

3

Explanation:

3

Answer:

physical sicence boilagiy sxcience and earth science

Explanation:

Answer:

It helps to reduce polution and gasses that damage our good gases and the greenhouse gases. It produces energy from the sun. It is the cleanest way to go!

Explanation:

Answer:

3.1556926 × 10^13 microseconds

Explanation:

Hope this helped!

if on the average every man lives for 70 years,  ​3.1556926 × 10^13 microseconds is this life span

life span of an organism can be defined as the period of time between the birth and death of an organism, it is a common place that all organisms die.

Some of the organism die after  a brief existence, for example mayfly, whose adult life burns out in a day, and  the gnarled bristlecone pines, which have lived thousands of years.

The limits of the life span of each species appear to be determined by heredity, it can be locked within the code of the genetic material  which are the instructions specify the age.

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Answer:

horizontal component=fcostita

=150cos60

use calculator to evaluate it

for vertical=fsintita

=150sin60

Answer:

eeeeeeeeeeeeeeeeeeeeeee

Answer:

a

Explanation:

A student bought a 1.55-ounce chocolate bar and left it in a car on a hot day.  Exactly 1.55 ounces of chocolate are in the melted bar. Hence, option (A) is correct.

In physics, mass is a quantitative measurement of inertia, a basic characteristic of all matter. It essentially refers to a body of matter's resistance to changing its speed or location in response to the application of a force.

The change caused by an applied force is smaller the more mass a body has. The kilogram serves as the unit of mass in the International System of Units (SI).

As mass does not depends on the state of the object, exactly same mass of chocolate are in the melted bar that it was in chocolate bar. So, 1.55 ounces of chocolate are in the melted bar. Hence, option (A) is correct.

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Answer:

It is neither false nor true. When they collide some of one of the objects goes to the other object.

Explanation:

Answer: True

Explanation:

Answer:

C

Explanation:

Since the net force is changing, and not the speed, it is C

Hope this helped!

Answer:

22 km/h

Explanation:

Given that,

Speed of Xavier, v = 14 km/h

He tosses a set of keys forward on the ground at 8 km/h, v' = 8 km/h

We need to find the speed of the keys relative to the ground. Let it is V.

As both Xavier and the keys are moving in same diretion. The relative speed wrt ground is given by :

V = v+v'

V= 14 + 8

V = 22 km/h

So, the speed of the keys relative to the ground is 22 km/h.

Answer:

The number of photons per second that strike the given area is 2.668 x 10⁸ photons/second

Explanation:

Given;

intensity of the sunlight, I = 2.00 kJ·s−1·m^−2

area of incident, A = 5.2 cm² = 5.2 x 10⁻⁴ m²

Energy of incident photons per second on the given area;

E = IA

E = (2000)( 5.2 x 10⁻⁴)

E = 1.04 J/s

Energy of a photon is given is by;

[tex]E = \frac{hc}{\lambda} \\\\E = \frac{(6.626*10^{-34})(3*10^8)}{(510*10^{-9})}\\\\E = 3.898*10^{-19} \ J/photon[/tex]

The number of photons per second that strike the given area is;

[tex]n = \frac{1.04 \ J/s}{3.898*10^{-19} \ J/photon} \\\\n = 2.668*10^{18} \ photons/second[/tex]

Therefore, the number of photons per second that strike the given area is 2.668 x 10⁸ photons/second

Answer:

Acceleration = 18g

Explanation:

Given the following data;

Initial velocity, u = 26m/s

Final velocity, v = 0

Time = 0.15 secs

To find the acceleration;

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

This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.

Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.

Mathematically, acceleration is given by the equation;

[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]

Substituting into the equation, we have;

[tex]a = \frac{0 - 26}{0.15}[/tex]

[tex]a = \frac{26}{0.15}[/tex]

Acceleration = 173.33m/s2

To express it in magnitude of g;

Acceleration = 173.33/9.8

Acceleration = 17.7 ≈ 18g

Acceleration = 18g

Answer:

750 nm

Explanation:

It is given that,

Third minimum is at an angle of 48.6º when it falls on a single slit of width 3.00 μm.

We need to find the wavelength of the light. For a single slit experiment, the relation between wavelength and slit width is given by :

[tex]d\sin\theta=n\lambda[/tex]

For third minimum, n = 3

[tex]\lambda=\dfrac{d\sin\theta}{n}\\\\\lambda=\dfrac{3\cdot10^{-6}\cdot\sin48.6}{3}\\\\\lambda=7.5\times 10^{-7}\ m\\\\\lambda=750\ nm[/tex]

So, the wavelength of light is 750 nm.

Answer:

A. 6.282

B. 2.03kg

Explanation:

A.

We solve using archimedes principle

L³pwood = L²dwater

We make d subject of the formula

d = Lpwood/pester

= 18x651/1000

= 18x0.651

= 11.718cm

Distance from horizontal top to water level

= 18-11.718

= 6.282cm

B.

When we place lead block

WL + L³pwoodg = L³pwaterg

WL = L³g(Pwater-Pwood)

= 0.18³x9.8(1000-651)

= 19.94N

19.94/9.8

= 2.03kg

The mass m is therefore 2.03kg

(a) The distance will be "6.282 cm".

(b) Mass will be "2.03 kg".

(a)

From Archimedes' principle, we get

→ [tex]L^3 \rho_{Wood} = L^2 d \rho_{Water}[/tex]

              [tex]d = L \frac{\rho_{Wood}}{\rho_{Water}}[/tex]

                 [tex]= 18\times \frac{651}{1000}[/tex]

                 [tex]= 11.72 \ cm[/tex]

So,

The distance from horizontal top to the water level will be:

= [tex]18-11.72[/tex]

= [tex]6.282 \ cm[/tex]

(b)

After placing the lead block of weight [tex]W_L[/tex], we have

→ [tex]W_L +L^3 \rho_{Wood} g = L_3 \rho_{Water} g[/tex]

                      [tex]W_L = L^3 g(\rho_{Water}-\rho_{Wood})[/tex]

                             [tex]= 0.18^3\times 9.8\times (1000-651)[/tex]

                             [tex]= 19.94 \ N[/tex]

Mass,

m = 2.03 kg  

Thus the above answer is right.

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Answer:

in the water cycle evaporation occurs when the sunlight warms the surface of the water the heat from the sun makes the water molecules move faster and faster until they move so fast they can escape as a gas once evaporated a molecule from water that vapor spends about 10 days in the air

Answer:

Explanation:

Step one:

given data

mass of ball m1=5kg

initial velocity of ball u1=10m/s

mass of pin m2=2kg

initial velocity of pin u2= 0m/s

final velocity of ball v2=8m/s

final velocity of pin v2=?

Step two:

The expression for elastic collision is given as

m1u1+m2u2=m1v1+m2v2

substituting we have

5*10+2*0=5*8+2*v2

50+0=40+2v2

50-40=2v2

10=2v2

divide both sides by 2

v2=10/2

v2=5m/s

The pin's final velocity is 5m/s

Answer:

D. will decrease slightly in volume when heated to 6° C

Explanation:

A gram of distilled water at 4° C  will increase slightly in volume when heated to 6 C. Hence option C is correct.

Water has the chemical formula H2O, making it an inorganic substance. It is the primary chemical component of the Earth's hydrosphere and the fluids of all known living things (in which it serves as a solvent[1]). It is translucent, flavourless, odourless, and almost colourless. In spite of not supplying food, energy, or organic micronutrients, it is essential for all known forms of life. Its molecules are made up of two hydrogen atoms joined by covalent bonds and have the chemical formula H2O. The angle at which the hydrogen atoms are joined to the oxygen atom is 104.45°.[2] The liquid condition of H2O at normal pressure and temperature is known as "water" as well.

Water occurs because the environment on Earth is pretty near to the triple point of water.

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Answer:

a

 [tex]\mu = 0.0023 \ A\cdot m^2[/tex]

b

[tex]\tau = 0.00080 \ N \cdot m[/tex]

Explanation:

From the question we are told that

  The dimensions of the  rectangular coil is 5.40 cm ✕ 8.50 cm  = 0.054 m X 0.085 m

   The  number of turns is  [tex]N = 25 \ turns[/tex]

   The current it  is carrying is  [tex]I = 20 \ mA = 0.02 \ A[/tex]

    The magnetic field is [tex]B = 0.350 \ T[/tex]

Generally the magnitude of the magnetic dipole moment is mathematically represented as

       [tex]\mu = N * I * A[/tex]

Here  A  is the area which is mathematically represented as

     [tex]A = 0.054 * 0.085[/tex]

=>  [tex]A = 0.00459 \ m^2[/tex]

So  

     [tex]\mu = 25 * 0.02 * 0.00459[/tex]

=>  [tex]\mu = 0.0023 \ A\cdot m^2[/tex]

Generally the  magnitude of the torque acting on the loop is mathematically represented as

    [tex]\tau = \mu * B[/tex]

=>[tex]\tau = 0.0023 * 0.350[/tex]

=>[tex]\tau = 0.00080 \ N \cdot m[/tex]

Answer:

A gravitational force of 6841.905 newtons is exerted on the satellite by the Earth.

Explanation:

At first we assume that Earth is represented by an uniform sphere, such that the man-made satellite rotates in a circular orbit around the planet. Hence, the following condition must be satisfied:

[tex]\left(\frac{4\pi^{2}}{T^{2}} \right)\cdot r = \frac{G\cdot M}{r^{2}}[/tex] (1)

Where:

[tex]T[/tex] - Period of rotation of the satellite, measured in seconds.

[tex]r[/tex] - Distance of the satellite with respect to the center of the planet, measured in meters.

[tex]G[/tex] - Gravitational constant, measured in newton-square meters per square kilogram.

[tex]M[/tex] - Mass of the Earth, measured in kilograms.

Now we clear the distance of the satellite with respect to the center of the planet:

[tex]r^{3} = \frac{G\cdot M\cdot T^{2}}{4\pi^{2}}[/tex]

[tex]r = \sqrt[3]{\frac{G\cdot M\cdot T^{2}}{4\pi^{2}} }[/tex] (2)

If we know that [tex]G = 6.67\times 10^{-11}\,\frac{N\cdot m^{2}}{kg^{2}}[/tex], [tex]M = 6.0\times 10^{24}\,kg[/tex] and [tex]T = 25800\,s[/tex], then the distance of the satellite is:

[tex]r = \sqrt[3]{\frac{\left(6.67\times 10^{-11}\,\frac{N\cdot m^{2}}{kg^{2}} \right)\cdot (6.0\times 10^{24}\,kg)\cdot (25800\,s)^{2}}{4\pi^{2}} }[/tex]

[tex]r \approx 18.897\times 10^{6}\,m[/tex]

The gravitational force exerted on the satellite by the Earth is determined by the Newton's Law of Gravitation:

[tex]F = \frac{G\cdot m\cdot M}{r^{2}}[/tex] (3)

Where:

[tex]m[/tex] - Mass of the satellite, measured in kilograms.

[tex]F[/tex] - Force exerted on the satellite by the Earth, measured in newtons.

If we know that [tex]G = 6.67\times 10^{-11}\,\frac{N\cdot m^{2}}{kg^{2}}[/tex], [tex]M = 6.0\times 10^{24}\,kg[/tex], [tex]m = 6105\,kg[/tex] and [tex]r \approx 18.897\times 10^{6}\,m[/tex], then the gravitational force is:

[tex]F = \frac{\left(6.67\times 10^{-11}\,\frac{N\cdot m^{2}}{kg^{2}} \right)\cdot (6105\,kg)\cdot (6\times 10^{24}\,kg)}{(18.897\times 10^{6}\,m)^{2}}[/tex]

[tex]F = 6841.905\,N[/tex]

A gravitational force of 6841.905 newtons is exerted on the satellite by the Earth.

Answer:

When we love someone we experience the same positive thoughts and experiences as when we like a person. But we also experience a deep sense of care and commitment towards that person. Being “in love” includes all the above but also involves feelings of sexual arousal and attraction.

Explanation:

Answer:

Explanation:

The mass of the car can be found by using the formula

[tex]m = \frac{f}{a} \\ [/tex]

f is the force

a is the acceleration

From the question we have

[tex]m = \frac{5500}{5} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

A plane mirror is placed to the right of an object. The image formed by the mirror will be a virtual image that appears to be on the left of the mirror.

Explanation:

B. KEsubbox = Esubtotal - mgh

If you are modeling a system in which an object’s total energy is conserved, you could express potential energy as the difference between total and kinetic, or, alternatively, you could model kinetic energy as the difference between total and potential.

Answer:

R₂₈₅₀ =  0.838 ohms

Explanation:

The resistance of an element at some other temperature than 0°C can be given by the following formula:

Rₓ = R₀(1 + ∝ΔT)

where,

Rₓ = Resistance at temperature x

R₀ = Resistance at 0°C

∝ = Coefficient of linear expansion of tungsten = 0.5 x 10⁻³ /°C

ΔT = Change in Temperature

So, for the resistance of tungsten wire at 25°C:

Rₓ = R₂₅ = 0.35 ohms

ΔT = 25°C

Therefore,

0.35 ohms = R₀[1 + (0.5 x 10⁻³ /°C)(25°C)]

R₀ = (0.35 ohms)/1.0125

R₀ = 0.345 ohms

Now, we find the resistance at 2850°C

R₂₈₅₀ = (0.345 ohms)[1 + (0.5 x 10⁻³ /°C)(2850°C)]

R₂₈₅₀ =  0.838 ohms

Answer:

600N

Explanation:

Answer:

θ = 122°

Explanation:

Components of a Vector

A vector in the plane can be defined by its rectangular components:

[tex]\vec A =<x,y>[/tex]

Or also can be given by its polar components:

[tex]\vec A =<r,\theta>[/tex]

Where r is the magnitude of the vector and θ is the angle it forms with the positive direction of x.

The relation between them is:

[tex]r=\sqrt{x^2+y^2}[/tex]

[tex]\displaystyle \theta=\arctan\frac{y}{x}[/tex]

It's given the x-component of vector A is x=-25 m and the y-component is y=40 m

(a)

The magnitude of the vector is:

[tex]r=\sqrt{(-25)^2+40^2}[/tex]

[tex]r=\sqrt{625+1600}[/tex]

[tex]r=\sqrt{2225}[/tex]

[tex]r\approx 47.2\ m[/tex]

(b)

[tex]\displaystyle \theta=\arctan\frac{40}{-25}[/tex]

[tex]\displaystyle \theta=\arctan (-1.6)[/tex]

The calculator gives us the value

θ = -58°

But the real angle lies on the second quadrant since x is negative and y is positive, thus:

θ = -58° + 180° = 122°

θ = 122°

Answer:

5 hours ................

Answer:

B=5 hrs

explanation:

becoz if you add 4 mph/hr

it will graually be 80 in 5 hrs

Answer:

e. none of these

Explanation:

An object in FREE-FALL on the MOON would experience only acceleration

Answer:

1. C

2. B

3. A

Explanation:

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