If μs is greater than some critical value, the woman cannot start the crate moving no matter how hard she pushes. calculate this critical value of μs.

Answer:

It will take it 4seconds.

Explanation:

The cheetah runs 25m for every 1s. So if you divide 100m by 25m the number of meters it runs in 1s, you will get 4s.

If the sun suddenly ceased to shine, then the earth will become dark after 8 min. The speed of light in a vacuum is given as 3* [tex]10^{8}[/tex] m/sec and the distance from the sun to earth is 148.97 million km.

Light moves at about 300,000 kilometers per second in a vacuum, which has a refractive index of 1.0, but it slows to 225,000 kilometers per second in water and 200,000 kilometers per second in glass, both of which have refractive indices of 1.3.

Given that in the question when sun ceased to shine than light on the earth will come after 8 min of ceasing because sunlight takes 8 min to reach on the earth. The speed of light in a vacuum is 186282 miles per second (299792 km/sec.

Light will come after 8 min when sun ceased to shine.

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Answer:

Kinetic energy, KE = 45 J

Explanation:

It is given that,

Force applied by girl on a sled, F = 15 N

It moves a distance, d = 3 m

We need to find the kinetic energy of the sled after she pulls it. We know that the work done is equal to the change in kinetic energy

[tex]W=\Delta E=K_f-K_i[/tex]

[tex]K_i=0[/tex] (initial at rest)

[tex]KE=W=F\times d[/tex]

[tex]KE=15\ N\times 3\ m=45\ J[/tex]

So, the kinetic energy of the sled after she pulls it is 45 J. Hence, this is the required solution.

To produce a net force of 200 N on a sled, a 300 N force and a 100 N force can combine if there is an opposing force of 200 N acting in the opposite direction.

In order to calculate the net force acting on the sled, we need to add the individual forces together. The 300 N force and the 100 N force are acting in the same direction, so we can simply add them together. 300 N + 100 N = 400 N. However, the question states that the net force on the sled is 200 N, so this means that there must be another force acting in the opposite direction. This opposing force must have a magnitude of 200 N in order for the net force to be 200 N.

An office heater that outputs 2050 BTUs of energy per hour can produce approximately 18,943.32 megajoules of energy per year when operated continuously, due to the conversion from BTU to kilojoules and then to megajoules.

The student wants to know how many megajoules of energy in the form of heat can be produced per year by a heater that puts out 2050 BTUs per hour. Since 1 BTU is equivalent to 1.055 kilojoules (kJ), we first convert the hourly heat output to kJ.

To find the yearly output in kJ, we multiply the hourly output by the number of hours in a year (24 hours/day × 365 days/year).

Thus, the heater can produce approximately 18,943.32 megajoules of heat energy per year if operated continuously.

Answer:

the answer is Miami-Dade

Explanation:

The bright, visible surface of the sun that we see from the earth is called the photosphere, which emits majority of light and has an average temperature of 5500 degrees Celsius.

The bright, visible surface of the sun that we see from Earth is known as the photosphere. The photosphere is the layer of the sun where the majority of the light is emitted. It's responsible for the visible light we see, and hence, it appears bright to us. The average temperature of the photosphere is approximately 5500 degrees Celsius. The sunspots, which are darker and cooler areas, can also be observed in this layer due to magnetic activity.

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Answer:

The likely result is that you die due to a strong discharge of electricity.

Explanation:

Electricity goes its way to the cities through a high voltage grid. Traveling over hundreds of kilometers of wire, electric power is very dangerous and can cause shock as a result of an electric shock that can kill any living thing. Falling, covered or empty power lines are very dangerous and should not be touched under any circumstances. These lines can contain high voltage energy and cause death if touched by someone who is not properly protected, so it can only be touched by professionals with proper protective equipment.

Answer:Mercury Earth Mars Saturn Neptune

Explanation:

Answer:

-3.2

Explanation:

This question involves the concept of magnification and image height.

The image height is "3.2 cm".

The magnification of a mirror can be given as the ratio of height of image to the height of object. It can also be given as the ratio of the distance of image from mirror to the distance of object from the mirror.

[tex]M = \frac{h_i}{h_o}=\frac{q}{p}[/tex]

where,

Therefore,

[tex]\frac{h_i}{8\ cm}=\frac{16\ cm}{40\ cm}\\\\h_i=\frac{(8\ cm)(16\ cm)}{40\ cm}[/tex]

[tex]h_i=3.2\ cm[/tex]

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The time for the feather to fall to the surface of the moon is about 1.29 seconds.

To determine the time for the feather to fall to the surface of the moon, we can use the equation:

distance = (initial velocity × time) + (0.5 × acceleration × time^2)

Since the feather is dropped, its initial velocity is 0 m/s. The distance is 1.40 meters and the acceleration is -1.67 m/s^2. Plugging these values into the equation and solving for time:

1.40 = 0.5 × (-1.67) × time^2

time^2 = -1.40 / (-0.5 × 1.67)

time^2 = 1.67

time ≈ √1.67

Using a calculator, the approximate value of √1.67 is 1.29 seconds. Therefore, it will take about 1.29 seconds for the feather to fall to the surface of the moon.

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The mass of the lead cylinder is 1963.53 grams.

Given that;

The mass of a cylinder of lead that is 1.80 in diameter, and 4.12 in long.

Now for the mass of a lead cylinder, use the formula:

Mass = volume × density

First, calculate the volume of the cylinder.

The volume of a cylinder is given by:

[tex]\text {Volume} = \pi r^2 h[/tex]

where r is the radius and h is the height.

Given that the diameter of the cylinder is 1.80 in,

Hence, find the radius by dividing it by 2:

Radius = 1.80 in / 2

Radius = 0.90 in

Next, convert the radius and height to the same unit as the density, which is grams per millilitre (g/ml).

Let's convert the dimensions to centimetres.

Since; 1 inch = 2.54 cm:

Hence, We get;

Radius = 0.90 in × 2.54 cm/in

           = 2.29 cm

Height = 4.12 in × 2.54 cm/in

           = 10.46 cm

Now, calculate the volume:

[tex]\text { Volume} = \pi \times (2.29 cm)^2 \times 10.46 cm[/tex]

             [tex]= 172.24 cm^3[/tex]

Since the density of lead is given as 11.4 g/ml, we need to convert the volume from cm³ to ml:

[tex]Volume = 172.24 cm^3 \times (1 ml / 1 cm^3)[/tex]

             [tex]= 172.24 ml[/tex]

Finally, calculate the mass using the formula:

Mass = Volume × Density

Mass = 172.24 ml × 11.4 g/ml

Mass = 1963.53 g

Therefore, the mass of the lead cylinder is 1963.53 grams.

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Final answer:

To find the mass of a lead cylinder with given dimensions and density, calculate the cylinder's volume in cubic centimeters (which equals milliliters), then multiply by the density of lead to find the mass in grams. The mass of the cylinder is approximately 1892.63 grams or 1.893 kg.

Explanation:

The student is asking for the mass of a cylinder of lead with a diameter of 1.80 inches and a length of 4.12 inches, given that the density of lead is 11.4 g/ml. To solve this, we first need to calculate the volume of the cylinder using the formula V = πr^2h, where V is volume, r is radius (half the diameter), and h is height (or length in this case). Then, we convert the volume into milliliters (since the density is given in g/ml) and use the density formula (mass = density × volume) to find the mass.

First, convert the dimensions to centimeters because the density is given in g/cm³ (1 inch = 2.54 cm).

This question is based on the fundamental principle of  laws of motion.

Before going to describe Newton's second law, first we fave to understand Newton's first law.As per Newton's first law it is impossible to change the state of rest or of uniform motion of an object along straight line unless and until it is compelled by external unbalanced force. It indicates that when there is a net or unbalanced force acts on  the body,it will undergo motion.. Balanced forces have no role in changing the state of motion or rest of the body.

Now we have to understand newton's second law. It states that the rate of change of momentum is directly proportional to the  applied force and takes place along the direction of force. Mathematically it is given by-

                                                [tex]F\alpha \frac{dp}{dt}[/tex]

Here p is the momentum and t is the time.

The symbol F in the above equation stands for the net force not on force only.It is so because the momentum of a body will change when there will be a net force acting on it.All the forces acting on the body can cot contribute to the motion.Some forces may cancel each other.Only the unbalanced or net force can do so.

Hence option  A is right.

Final Answer:

a) 1960 m

b) 1860 m

Explanation:

a) When the balloon is at rest, the height it was dropped from can be calculated using the formula for free fall: [tex]\( h = \frac{1}{2} g t^2 \)[/tex], where h is the height, g is the acceleration due to gravity, and t is the time taken. Substituting the given values, we find [tex]\( h = \frac{1}{2} \times 9.8 \, \text{m/s}^2 \times (20 \, \text{s})^2 = 1960 \, \text{m} \)[/tex].

b) If the balloon is ascending with a speed of 50 m/s when the bottle is dropped, we subtract the distance traveled by the balloon in 20 s from the height calculated in part (a). The distance traveled by the ascending balloon is [tex]\( 50 \, \text{m/s} \times 20 \, \text{s} = 1000 \, \text{m} \)[/tex]. Therefore, the height of the balloon is [tex]\( 1960 \, \text{m} - 1000 \, \text{m} = 960 \, \text{m} \)[/tex].

Final answer:

The chronological order of events according to the Big Bang theory begins with the formation of hydrogen and helium atoms a few seconds after the Big Bang, followed by the formation of protostars and stars around 400 to 500 million years later. Subsequent events include the creation of heavier elements through supernova explosions, culminating in the formation of our Sun and the Earth about 9 billion years after the Big Bang.

Explanation:

To put each event in order of its occurrence according to the Big Bang theory, we can use our knowledge of cosmic history and the timelines provided by theoretical predictions and observational evidence to create a chronological list.

Formation of hydrogen and helium atoms - This event occurs a few seconds after the Big Bang, when the universe was extremely hot and dense, allowing for the creation of protons, neutrons, and eventually leading to the formation of hydrogen and helium nuclei.

Formation of large nebulae into protostars and eventually full-blown stars - About 400 to 500 million years after the Big Bang, the universe had expanded and cooled enough for the first stars and galaxies to begin forming from large clouds of gas.

Early massive stars exploded producing supernovae and heavier elements - This process of star formation and destruction, including supernovae, would have begun relatively soon after the first stars formed and continued throughout the history of the universe, enriching the interstellar medium with heavier elements over time.

Formation of our Sun and the Earth - Our solar system, including the Sun and Earth, formed about 9 billion years after the Big Bang, from the gravitational collapse of a region within a large molecular cloud.

The velocity of the speeder is expressed by the equation:

v1 = d1 / t1 --> d1 = v1 t1

And for the police:

d2= v2i t2 + 0.5 a2 t2^2

where v is final velocity, vi is initial velocity, d is distance, a is acceleration and t is time

The distance of the two must be equal when the police overtakes the speeder hence:

v1 t1 = v2i t2 + 0.5 a2 t2^2

t1 = t2 = t and v2i = 0 since the police starts at rest, so:

26.8 t = 0.5 * 2.4 * t^2

26.8 = 1.2 t

t = 22.33 seconds

Answer:

[force hope this help]

Explanation:

Answer:

9264706 molybdenum atoms have to be laid.

Explanation:

The parameter of the atom which  will determine the number of atoms needed to span a certain distance is the diameter. Diameter (d) is simply two times radius(r):

[tex]d=2r=2*136pm=272pm[/tex] (eq. 1)

If we express the number of molybdenum atoms needed with the letter x, the spanned distance (2.52mm) has to be equal to the number of atoms (x) times the diameter of these atoms.

[tex]2.52mm=x*d[/tex] (eq 2.)

Before stating an equation, all units have to be consistent (272 picometres expressed in mm, or 2.52mm expressed in pm, either one). Let's convert 272pm, using a conversion factor:

Conversion factor: [tex]1mm=1*10^9pm[/tex]

[tex]272pm=272pm*(\frac{1mm}{1*10^9pm})=2.72*10^-7mm[/tex]

Now, solving for "x" in the second equation:

[tex]x=\frac{2.52mm}{d}[/tex]

Plugging in the "d" value:

[tex]x=\frac{2.52mm}{2.72*10^-7mm}=9264706[/tex]