A sled of mass 50 kg is pulled along a snow-covered, flat ground. The static friction coefficient is 0.3 and the kinetic friction coefficient is 0.1.
Draw a FBD of all the forces acting on the sled.
What is the weight of the sled?
What force is needed to start the sled moving?
What force is needed to keep the sled moving at a constant velocity?

Answer:

10 mph faster than car 1 is going

Explanation:

Answer:

The value is [tex]N = 1.107 *10^{45 } \ photons[/tex]    

Explanation:

From the question we are told that

   The  power output from the sun is  [tex]P_o = 4 * 10^{26} \ W[/tex]

   The average wavelength of each photon is  [tex]\lambda = 550 \ nm = 550 *10^{-9} \ m[/tex]

Generally the energy of each photon emitted is mathematically represented as

        [tex]E_c = \frac{h * c }{ \lambda }[/tex]

Here  h is the Plank's constant with value  [tex]h = 6.62607015 * 10^{-34} J \cdot s[/tex]

          c is the speed of light with value  [tex]c = 3.0 *10^{8} \ m/s[/tex]

So

       [tex]E_c = \frac{6.62607015 * 10^{-34} * 3.0 *10^{8} }{ 550 *10^{-9} }[/tex]          

=>   [tex]E_c = 3.614 *10^{-19} \ J[/tex]          

Generally the  number of photons emitted by the Sun in a second is mathematically represented as

         [tex]N = \frac{P }{E_c}[/tex]

=>      [tex]N = \frac{4 * 10^{26} }{3.614 *10^{-19}}[/tex]

=>      [tex]N = 1.107 *10^{45 } \ photons[/tex]    

Answer:

Oppositely charged objects will exert an attractive influence upon each other. In contrast to the attractive force between two objects with opposite charges, two objects that are of like charge will repel each other.

Explanation:

Answer:

0.37 m

Explanation:

Let the shoulder be the origin.

The center of mass of the arm bones is 0.60 m/2 = 0.30 m and the center of mass of the hand bones is 0.10 m/2 = 0.05 m since they are modeled as straight rods with uniform density and the center of mass of a rod is x = L/2 where L is the length of the rod.

The center of mass y = (m₁y₁ + m₂y₂)/(m₁ + m₂) where m₁ = mass of arm bones = 4.0 kg, y₁ = distance center of mass of arm bones  from shoulder = 0.30 m, m₂ = mass of hand bones = 1.0 kg and y₂ = distance of center of mass hand bones from shoulder = x₁ + distance of center of hand bones from wrist = 0.60 m + 0.05 m = 0.65 m

Substituting these into the equation for the center of mass, we have

y = (m₁y₁ + m₂y₂)/(m₁ + m₂)

y = (4.0 kg × 0.30 m + 1.0 kg × 0.65 m)/(4.0 kg + 1.0 kg)

y = (1.20 kgm + 0.65 kgm)/5.0 kg

y = 1.85 kgm/5.0 kg

y =  0.37 m

The distance of the center of mass from the shoulder is thus y = 0.37 m

Answer:

58.56 J

Explanation:

Since the formula for gravitational potential energy is:

GE = m x g x h - where m = mass (kg), g = acceleration due to gravity (9.81 m/s²), h = height (m)

GE= 3 x 9.81 x 2

GE = 58.86 J

Hope this helps

Answer: no because you have left the number

Explanation:

Answer:

The value is  [tex]\theta = 16.38^o[/tex]

Explanation:

From the question we are told that

    The  radius is  [tex]r = 50 \ m[/tex]

    The  velocity is  [tex]v = 12 \ m/s[/tex]

Generally the angle is mathematically represented as

          [tex]\theta = tan^{-1} [\frac{v^2}{ gr} ][/tex]

=>       [tex]\theta = tan^{-1} [\frac{12^2}{ 9.8 * 50 } ][/tex]

=>       [tex]\theta = tan^{-1} [ 0.2939 ][/tex]

=>        [tex]\theta = 16.38^o[/tex]

Answer:

2.51 kg * m/s

Explanation:

In order to find momentum, use the equation below:

momentum = mass * velocity.

Since neither mass nor velocity was given, you must solve for both variables.

In order to solve for mass, use the force equation for its weight / gravitational force.

Fg (gravitational force) = 3.2 N = ma = 9.8m

mass = 3.2 N / 9.8 m/s^2 = 0.326531 kg

In order to solve for velocity, use the equation:

velocity = displacement / time

velocity = 10m / 1.3 s = 7.69231 m/s

Momentum = mass * velocity = 0.326531 kg *  7.69231 m/s = 2.51177 kg * m/s = 2.51 kg * m/s

Answer:

The answer is "wedge​"

Explanation:

A wedge is an item that tightens to a meager edge. Pushing the wedge one direction makes a force in a sideways direction. It is normally made of metal or wood and is used for parting, tightening, lifting, or fixing, as in making sure about a hammer head onto its handle.

The wedge was used in ancient occasions to part logs and shakes; an ax is also a wedge, similar to the teeth on a saw. As far as its mechanical capacity, the screw might be considered as a wedge folded over a cylinder.

Answer:

B. Density

Explanation:

Thermal expansion of a gas will cause a definite change in the density of the gas.

It is product of an increase in the average kinetic energy of the system in which molecules are found.

Therefore, thermal expansion of gas will cause a change in the density of the gas.

Answer:

The second one I think

Explanation:

B

Answer:

Capital (G) is a universal gravitation law. and small (g) is acceleration of gravity of the each (9.8m/s^2)

Explanation:

According to the web

Answer:

Explanation:

The formula for weight is

W = mg, where

W = the weight of the object or person

m = mass of the object or person

g = acceleration due to gravity

Now, we're given the mass of the person to be 60 kd, and thus, the weight of that person would be

W = 60 * 9.81

W = 588.6 N

On the surface of the moon, the weight of the person would be

W = 60 * 1.625

W = 97.5 N

Therefore, the weight of the person on both surfaces are 588.6 and 97.5 respectively

Answer:

the motion of the coin taping the balloon is the balloon squshing down

Answer:

93.125 × 10^(19)

Explanation:

We are told the asteroid has acquired a net negative charge of 149 C.

Thus;

Q = -149 C

charge on electron has a value of:

e = -1.6 × 10^(-19) C

Now, for us to determine the excess electrons on the asteroid, we will just divide the net charge in excess on the asteroid by the charge of a single electron.

Thus;

n = Q/e

n = -149/(-1.6 × 10^(-19))

n = 93.125 × 10^(19)

Thus, it has 93.125 × 10^(19) more electrons than protons

Explanation:

ans is equal to 504j* 23 m* 10 ms

Hello!!

For the maximum height the final velocity is zero, because can't up more.

Then, use the formula:

V = Vi + gt

Replacing, we have:

0 m/s = 5,3 m/s + (-9,8 m/s² * t)

0 m/s - 5,3 m/s = -9,8 m/s² * t

(-5,3 m/s) / -9,8 m/s² = t

t = 0,54 s

The time it will take to reach the maximum height is 0,54 seconds.

Given :

The mass of the balloon was 1890 kg and had a volume of 11,430 m3 .

The balloon floats at a constant height of 6.25m above the ground.

To Find :

The density of the hot air in the balloon.

Solution :

We know,

Volume × ( Density of surrounding air - Density of hot air ) = mass

Putting given values in above equation, we get :

[tex]11430\times ( 1.29 - \rho_{hot \ air } ) = 1890\\\\\rho_{hot \ air } = 1.29 - \dfrac{1890}{11430}\\\\\rho_{hot \ air } = 1.125\ kg\ m^3[/tex]

Therefore, the density of hot air in the balloon is 1.125 kg m³.

Answer:

satellite technology helped large ocean liners guide you to our space mission.

Explanation:

Large ocean liners use satellites to aid in navigation. This type of navigation aid is also used on cruise ships. Using satellites can help these large ships navigate waters during bad storms.

Satellite surveillance can be used to aid in port security. Satellite data can be monitored and evaluated by complex computer systems. These systems can alert officials when something unusual occurs.

Satellite technology allows us to monitor and track the changes in the polar ice sheets. This can help us plan and direct conservation efforts for the animals that depend on polar ice in order to survive.

Satellite surveillance has allowed us to map areas that were previously too remote to observe. This helps developers to locate and choose sites for large resorts.

Answer:

Positively Charge formation on the electroscope pulls the electrons so no emission happens.

Explanation:

Photoelectric effect is the process by which the electrons get ejected when light of certain frequency falls on the material. The energy from the electromagnetic radiation excites the electron by providing it enough energy as a result it gets ejected.

The Ultraviolet(UV) light is a form of electromagnetic radiation, If the UV radiation strikes an uncharged electroscope, it is predicted that it will cause the electrons in the electroscope to excite and to be emitted.  But on the contrary no noticeable effect is observed on the electroscope this happened because when UV light makes the electroscope positively(+) charged this creates a pull for the electrons, as a result rather emitting the electrons gets pulled by the positively charged electroscope.

Therefore the positively charge formation on the electroscope hinder the electrons emission and there is no noticeable effect.  

Answer:

52,163.1

Explanation:

Answer:

The magnitudes of the speed and acceleration of the Earth are approximately 66,661.217 miles per hour and 47.782 miles per square hour, respectively.

Explanation:

Given that the Earth has a circular orbit and make a revolution at constant speed around the Sun. Then, the kinematic formulas for the speed and acceleration of the planet are, respectively:

Speed

[tex]v = \frac{2\pi\cdot R}{T}[/tex] (1)

Acceleration

[tex]a = \frac{4\pi^{2}\cdot R}{T^{2}}[/tex] (2)

Where:

[tex]v[/tex] - Speed of the planet, measured in miles per hour.

[tex]a[/tex] - Acceleration of the planet, measured in miles per square hour.

[tex]R[/tex] - Radius of the orbit, measured in miles.

[tex]T[/tex] - Period of rotation, measured in hours.

If we know that [tex]R = 93,000,000\,mi[/tex] and [tex]T = 8,765.76\,h[/tex], then the magnitudes of the speed and acceleration of the planet is:

[tex]v = \frac{2\pi\cdot (93,000,000\,mi)}{8,765.76\,h}[/tex]

[tex]v \approx 66,661.217\,\frac{mi}{h}[/tex]

[tex]a = \frac{4\pi^{2}\cdot (93,000,000\,mi)}{(8,765.76\,h)^{2}}[/tex]

[tex]a\approx 47.782\,\frac{mi}{h^{2}}[/tex]

The magnitudes of the speed and acceleration of the Earth are approximately 66,661.217 miles per hour and 47.782 miles per square hour, respectively.

Answer:  The initial volume of the gas is 7.72 L

Explanation:

For an isothermal process the temperature is constant.  

[tex]PV=nRT[/tex]

as P = pressure = 1 atm ,

V = Volume =  25 L

n = moles

R= gas constant

T = temperature

[tex]PV=1atm\times 25L[/tex]

[tex]nRT=25Latm=25\times 101.3J=2532.5J[/tex]     (1Latm=101.3 J)

For isothermal reaction :

[tex]w=-2.303nRT\log\frac{V_2}{V_1}[/tex]

where , w = work done by  system = -ve

n = moles = 1

[tex]V_2[/tex] = final volume = 25 L

[tex]V_1[/tex] = initial volume = ?

[tex]-3000J=-2.303\times 2532.5\log \frac{25}{V_1}[/tex]

[tex]V_1=7.72L[/tex]

Thus initial volume of the gas is 7.72 L

Answer:

Horizontal distance covered is  270.63ft

Time of flight is 3.125secs

Height to which it rises is 39.06feet

Explanation:

The horizontal distance covered is the range;

Range = U²sin2theta/g

Range = 100²sin2(30)/32

Range = 10000sin60/32

Range = 10000(0.8660)/32

Range = 8660/32

Range = 270.625ft

Hence the  horizontal distance covered is  270.63ft

The time of flight is expressed using the formula;

T = 2Usin theta/g

g is the acceleration due to gravity

T = 2(100)sin30/32

T = 200(0.5)/32

T = 100/32

T = 3.125secs

Hence the time of flight is 3.125secs

Maximum height H = u²sin²theta/2g

H = 100²(sin30)²/2(32)

H = 10000(0.5²)/64

H = 10000(0.25)/64

H = 2500/64

H = 39.0625

Hence the height to which it rises is 39.06feet

Answer: a. nuclear fission.

Explanation:

Nuclear power plants use heavy materials, like uranium 238, which is bombarded with neutrons. When the neutrons interact with the uranium, there is fission (a division of one atom into smaller ones and other subatomic particles), and in this process, more neutrons are produced. These new neutrons may impact other atoms of uranium and continue with this cycle, generating heat in the process.

Then we can conclude that nuclear power plants produce energy using nuclear fission.

Answer:

The value is  [tex]v = 2.3359 *10^{4} \ m/s[/tex]

Explanation:

From the question we are told that

  The  initial speed is [tex]u = 2.05 *10^{4} \ m/s[/tex]

 Generally the total energy possessed by the space probe when on earth is mathematically represented as

             [tex]T__{E}} = KE__{i}} + KE__{e}}[/tex]

Here  [tex]KE_i[/tex] is the kinetic energy of the space probe due to its initial speed which is mathematically represented as

          [tex]KE_i = \frac{1}{2} * m * u^2[/tex]

=>       [tex]KE_i = \frac{1}{2} * m * (2.05 *10^{4})^2[/tex]

=>       [tex]KE_i = 2.101 *10^{8} \ \ m \ \ J[/tex]

And  [tex]KE_e[/tex] is the kinetic energy that the space probe requires to escape the Earth's gravitational pull , this is mathematically represented as

       [tex]KE_e = \frac{1}{2} * m * v_e^2[/tex]

Here [tex]v_e[/tex] is the escape velocity from earth which has a value [tex]v_e = 11.2 *10^{3} \ m/s[/tex]

=>    [tex]KE_e = \frac{1}{2} * m * (11.3 *10^{3})^2[/tex]

=>    [tex]KE_e = 6.272 *10^{7} \ \ m \ \ J[/tex]

Generally given that at a position that is very far from the earth that the is Zero, the kinetic energy at that position is mathematically represented as

        [tex]KE_p = \frac{1}{2} * m * v^2[/tex]

Generally from the law energy conservation we have that

        [tex]T__{E}} = KE_p[/tex]

So

       [tex]2.101 *10^{8} m + 6.272 *10^{7} m = \frac{1}{2} * m * v^2[/tex]

=>     [tex]5.4564 *10^{8} = v^2[/tex]

=>     [tex]v = \sqrt{5.4564 *10^{8}}[/tex]

=>     [tex]v = 2.3359 *10^{4} \ m/s[/tex]