A needle 5cm long can just rest on the surface of the water without wetting. What us it's weight? Surface tension is 0.007N/m​

Answer:

mass

Explanation:

The effective resistance of many individual resistors in series is the sum of the individual resistances.

50 items in series, each with a resistance of 15 ohms, are equivalent to a single resistance of (15 x 50) = 750 ohms.

By the way . . . If one of the little bulbs in series burns out, all the others do NOT burn out. They simply get turned off and go dark, because the current can't flow through the one that did.

The total resistance of the string of fifty 15 ohm Christmas tree lights that are connected in series is 750 ohms.

The total resistance of the series resistors is determined by adding all the componenets of the resistors together.

Rt = R1 + R2 + R3 + ----

where;

Rt = 50 x (15 ohms)

Rt = 750 ohms

Thus, the total resistance of the string of fifty 15 ohm Christmas tree lights that are connected in series is 750 ohms.

Learn more about total resistance here: https://brainly.com/question/2980867

#SPJ2

Answer: 4575N

Explanation:

For y component, W = mgcosø

W = 500×9.8cos21

W = 4574.54N

Find the diagram in the attached file

Answer:

-45.745

Explanation:

negative because it is downward

Answer:

0 J

Explanation:

The mechanical energy of a spring is given by [tex]0.5kx^{2}[/tex] where k is spring constant and x is extension of spring. Since the spring is unstretched,  its extension is zero.

#Notice that the potential energy is 0.

-Substituting spring constant,  k with 8 and extension with zero then the mechanical energy will be

[tex]0.5\times 8\times 0^{2}=0 J[/tex]

Answer:True

Explanation:

if you were to swim alone and something bad happen and there was none on the beach you'd be stuck out so NEVER swim alone :)

Answer:

When a particle or a system of particles move in a system where no external force acts, then the total linear momentum of the particle system remains constant.

Explanation:

Given data:

Total mass of the skateboarder, [tex]m_{1} = 70 \ kg[/tex]

Mass of the friend, [tex]m_{2} = 50 \ kg[/tex]

Initial velocity of the skateboarder, [tex]u_{1} = 3 \ m/s[/tex]

Initial velocity of the the friend, [tex]u_{2} = 0[/tex]

Let the new velocity of the skateboarder when his friend jumps be [tex]v[/tex].

From the conservation law of linear momentum,

[tex]m_{1}u_{1} + m_{2}u_{2} = (m_{1} + m_{2})v[/tex]

[tex]70 \times 3 + 50 \times 0 = (70 + 50)v[/tex]

[tex]\Rightarrow \ v &= 1.75 \ m/s.[/tex]

Answer:

-16 kg m/s

Explanation:

Momentum is a vector quantity indicating the "amount of motion" in an object.

The change in momentum of an object is given by:

[tex]\Delta p = m(v-u)[/tex]

where:

m is the mass of the object

u is its initial velocity

v is its final velocity

For the water balloon in this problem, we have:

m = 0.50 kg is the mass

u = 32 m/s is the initial velocity

v = 0 m/s (since the balloon comes to a stop)

Therefore, the change in momentum is:

[tex]\Delta p=(0.50)(0-32)=-16 kg m/s[/tex]

And the negative sign indicates that the direction is opposite to the initial velocity.

Answer:

its velocity is 51, or 51.42 to be exact it would be: 51.4285714286

Answer:

[tex]2.19\cdot 10^{13}[/tex]

Explanation:

The electron is a fundamental particle, with a charge of

[tex]e=-1.6\cdot 10^{-19}C[/tex]

which is also known as fundamental charge.

For an object having N excess electrons, the total charge on the object is

[tex]Q=Ne[/tex] (1)

where e is the charge of the electron.

For the object in this problem, its charge is

[tex]Q=+3.5\cdot 10^{-6} C[/tex]

This can be obtained by removing a negative charge equal to

[tex]Q=-3.5\cdot 10^{-6}C[/tex]

Substituting into (1) and solving for N, we can find the number of electrons:

[tex]N=\frac{Q}{e}=\frac{-3.5\cdot 10^{-6}}{-1.6\cdot 10^{-19}}=2.19\cdot 10^{13}[/tex]

Answer:

True

Explanation:

Answer:

Al2O3 + 3Mg ===》 3MgO + 2Al

Explanation:

Reaction of aluminium oxide with magnesium metal would form magnesium oxide and aluminium metal.

Balancing the stoichiometric equation, the number of atoms at the reactant must be equal to the number of atoms at the product so that law of conservation of matter must hold.

Al203 + 3Mg ====》 3MgO + 2Al

2 aluminium at reactant = 2 aluminium at product

3 oxygen at reactant = 3 oxygen at product

3 magnesium at reactant = 3 magnesium at product.

agitate... hope this helps.......

In Chemistry, to accelerate a reaction often involves using a catalyst to increase the reaction rate without the catalyst being consumed. Acceleration in Physics refers to a change in an object's velocity, as described by Newton's first law of motion.

The term 'to accelerate' typically implies speeding up any process or reaction. In the context of Chemistry, this often refers to increasing the rate at which a chemical reaction occurs. Factors that can accelerate a reaction include stirring, increasing temperature, or adding a catalyst. A catalyst is a substance that increases the speed of a reaction without being consumed in the process. Acceleration, specifically in Physics, is defined as the change in velocity - which can be in the magnitude or direction or both. Newton's first law of motion, also known as the law of inertia, states that a body at rest remains at rest, and a body in motion remains in motion at a constant velocity unless acted upon by a net external force — implying the role of acceleration when this state is altered.

Answer:

The correct answers are "chemical energy into electrical energy" and then "the electrical energy into light energy". Explanation: In the battery-powered flashlight, the battery supplies the chemical energy which makes the electrons to flow in the circuit and constitutes the current

Explanation:

When a plastic lid is sprinkled with iron filings is placed over a magnet then a pattern is formed. The iron fillings arrange themselves in a way how magnetic field is present. The force of the magnet is the strongest at the two ends because more iron particles are concentrated in these areas. The magnetic lines of flux flow from one end to the other.

Answer:

Time, t = 28.22 s.

Explanation:

Given data:

Power, [tex]P = 1750 \ \rm W[/tex]

Mass, [tex]m = 315 \ kg[/tex]

Height, [tex]h = 16.0 \ m[/tex]

Let the time required to lift the piano to 16.0 m above be t.

We know that,

[tex]P = \frac{W}{t}[/tex]

[tex]P = \frac{mgh}{t}[/tex]

[tex]\Rightarrow \ t = \frac{mgh}{P}[/tex]

[tex]t = \frac{315 \times 9.80 \times 16.0}{1750}[/tex]

[tex]t = 28.22 \ s.[/tex]

It will take the motor 28.224 seconds to lift the piano to the sixth-story window.

Given the following data;

We know that acceleration due to gravity is equal to 9.8 m/s².

To find how long it will take to lift the piano to the sixth-story window;

First of all, we would have to determine the gravitational potential energy required to lift the piano up.

Mathematically, gravitational potential energy is calculated by using the formula;

[tex]G.P.E = mgh[/tex]

where:

Substituting into the formula, we have;

[tex]G.P.E = 315 \; * \; 9.8 \; * \; 16[/tex]

G.P.E = 49,392 Joules

Next, we would determine the time using the following formula;

[tex]Time = \frac{Energy}{Power}[/tex]

Substituting the values into the formula, we have;

[tex]Time = \frac{49392}{1750}[/tex]

Time = 28.224 seconds

Therefore, it will take the motor 28.224 seconds to lift the piano to the sixth-story window.

Find more on power, time and energy here: brainly.com/question/20488953

Answer:

Now since mass of reactant is equal to mass of the product after the reaction so we can say that mass conservation is applicable here

Explanation:

As we know that zinc reacts with copper sulfate

so the reaction is given as

[tex]Zn + CuSO_4 --> ZnSO_4 + Cu[/tex]

so here we have

[tex]Zn = 10.1 g[/tex]

[tex]CuSO_4 = 18.6 g[/tex]

[tex]ZnSO_4 = 20 g[/tex]

[tex]Cu = 8.7 g[/tex]

Now total mass of reactant is given as

[tex]M_1 = 10.1 + 18.6 = 28.7 g[/tex]

Mass of the product is given as

[tex]M_2 = 20 + 8.7 = 28.7 g[/tex]

Now since mass of reactant is equal to mass of the product after the reaction so we can say that mass conservation is applicable here

Answer:25N/M^2

Explanation:

Force=20N Area=0.8M^2

Stress=force/area

Stress=20/0.8

Stress=25N/M^2

Answer:

78.4 J

Explanation:

The gravitational potential energy of an object is the energy possessed by the object due to its location in the gravitational field.

The change in gravitational potential energy of an object is given by:

[tex]\Delta U=mg\Delta h[/tex]

where:

m is the mass of the object

[tex]g=9.8 m/s^2[/tex] is the acceleration due to gravity

[tex]\Delta h[/tex] is the change in height of the object

For the mass in  this problem, we have:

m = 2 kg is the mass

[tex]\Delta h = 4 m[/tex] is the change in height

So, its change in gravitational energy is:

[tex]\Delta U=(2)(9.8)(4)=78.4 J[/tex]

Answer:

25116 J

Explanation:

The amount of heat required to raise the temperature of a substance is given by the equation

[tex]Q=mC\Delta T[/tex]

where

m is the mass of hte substance

C is the specific heat capacity of the substance

[tex]\Delta T[/tex] is the change in temperature

For the sample of water in this problem, we have:

m = 0.20 kg is the mass

[tex]C=4186 J/kg^{\circ}C[/tex] is the specific heat of water

[tex]\Delta T=45-15=30^{\circ}C[/tex] is the increase in temperature

Therefore, the amount of heat required is

[tex]Q=(0.20)(4186)(30)=25116 J[/tex]

Answer:

Yes they do

Explanation:

All waves (both transverse and longitudinal) transfer energy from one point to another.

(e.g think about sound waves (longitudinal) and light waves (transverse))

Answer: 6m/s²

Explanation:

Acceleration = change in velocity / time

Initial velocity = 4m/s

Final velocity = 22m/s

Time = 3s

Acceleration = (22 - 4) / 3

a = 18 / 3 = 6m/s²

100° C she can expect once the water begins to boil.

Option: B

Explanation:

The boiling point for water at 1 pressure atmosphere of sea level is 212 ° F or 100 ° C. That value isn't a fixed. Water's boiling point is dependent on the ambient pressure, which varies based on elevation. At a lower temperature, water boils as one gains altitude like getting higher on a hill, and boils at a higher temperature if one increases the atmospheric pressure of returning to or below sea level.

It also relies upon the water's purity. Water containing contaminants like salted water boils at a level higher than pure water. This effect is called acceleration of the boiling point and is one of the material's colligative features.

Answer:

option b) 100°

Explanation:

The Acceleration of  slug  would be 2 mm/hr²

Step by step Explanation:

Given of the solution

Initial velocity of the slug,(we can represent as [tex]v_{i}[/tex])  [tex]v_{i}[/tex]= 3 mm/hr

Final velocity of the slug,(we can represent as [tex]v_{f}[/tex] ) [tex]v_{f}[/tex]= 5 mm/hr

Time, t = 1 hr

Acceleration, a = ?

We know,

[tex]a = \frac{(5-3)}{1} \\\\a = 2 mm/hr^2[/tex]

Therefore, The Acceleration of  slug would be 2 mm/hr²

Answer:

Explanation:

momentum is written as p

p = mass * velocity

p = mv

30 km per hr = 30 * 1000 meters per 3600 seconds

velocity = 30000 meters per 3600 seconds

p = mv

p = 75 * 30000 / 3600

p = 625 kilogram per meter second

I hope my answer helps you and is correct

Please mark as brainliest

The momentum of an adult female weighing 75 kg and riding a bicycle at 30 km/h (8.33 m/s) is 625 kg·m/s.

To calculate the momentum of an adult female riding a bicycle, we use the formula for linear momentum, which is momentum (p) = mass (m) × velocity (v). First, we need to convert the velocity from kilometers per hour (km/h) to meters per second (m/s) since the standard unit for velocity in physics is m/s. The conversion is as follows: 30 km/h = 30 × (1000 m/3600 s) = 8.33 m/s. The mass of the adult female is given as 75 kg.

Therefore, the momentum of the adult female riding a bicycle is:

p = m × v = 75 kg × 8.33 m/s = 625 kg·m/s.

Answer:

Explanation:

The moving charged particles in an electric current are called charge carriers. In metals, one or more electrons from each atom are loosely bound to the atom, and can move freely about within the metal. These conduction electrons are the charge carriers in metal conductors.

The flow of electrons in a direction is known as electric current. The tendency of attraction between the positive and negative charges makes electric current flow through a wire

An electrical charge, being either positive or negative, is a property that causes particles to experience force within an electric field. Electric current is the flow of these charges, driven by voltage sources such as batteries, across conductive materials. The current's strength is influenced by the applied voltage and the material's resistivity.

What is Electrical Charge and How Does it Create Electrical Current?

Electrical charge is a fundamental property of particles that causes them to experience a force when placed in an electric field. There are two types of charge, positive and negative, and like charges repel each other while opposite charges attract. This concept of charge is crucial in explaining how electric currents are created and maintained.

An electric current is the rate of flow of electric charge through a conductor, such as a wire. In metals, the charge carriers are primarily electrons, which are negatively charged particles that move through the metal's lattice when a potential difference (voltage) is applied across the conductor. This movement of charge constitutes the electric current.

Devices like batteries and generators create a potential difference in a circuit, and consequently an electrical field, which pushes the free charges to move. The amount of current that flows depends on both the voltage applied and the resistivity of the material through which charges are moving. Resistivity is a measure of how strongly a material opposes the flow of electric current, and it varies from material to material.

In different mediums, various charged particles may carry the current. In our bodies, for instance, current is carried by ions such as sodium ions (Na+), while in metal wires, it is carried by electrons. The existence of an electric current is fundamental to our technology, as it powers everything from simple torches to complex electric trains and computers, and even the neuronal activities in our brains.

Charges are responsible for creating electric fields, which can attract or repel other charges depending on their polarity. Positive charges are sources of electric fields, while negative charges act as sinks. It is this interplay between charges and electric fields that permits the generation and control of electric currents, leading to our ability to harness electricity for countless applications.

Answer:

Newton

Explanation:

Newton is the correct unit for a force

Answer:

[tex]41.3 m/s^2[/tex]

Explanation:

The acceleration of an object is the rate of  change of the velocity of the object.

It is a vector quantity, so it has a magnitude and a direction.

The acceleration is given by:

[tex]a=\frac{v_f-v_i}{t}[/tex]

where

[tex]v_f[/tex] is the final velocity

[tex]v_i[/tex] is the initial velocity

t is the time taken for the velocity to change

If the acceleration is positive, the direction is the same as the initial velocity; if the acceleration is negative, the direction is opposite to the initial velocity.

In this problem:

[tex]v_i=0[/tex] is the initial velocity

[tex]v_f=124 m/s[/tex] is the final velocity

t = 3 s is the  time

So, the acceleration is

[tex]a=\frac{124-0}{3}=41.3 m/s^2[/tex]

answer: 340 m/s

explanation: in this instance, the sound wave travels 340 meters in 1 second, so the speed of the wave is 340 m/s. remember, when there is a reflection, the wave doubles its distance. in other words, the distance traveled by the sound wave in 1 second is equivalent to the 170 meters down to the canyon wall plus the 170 meters back from the canyon wall.

The speed of the wave is 340 m/s. It can be calculated by dividing distance by time.

Given:

Distance = 170 meters

Time = 1 Seconds

It is defined as the ratio between distance and time.

Speed = Distance /  Time

In this instance, The sound wave travels 340 meters in 1 second, So the speed of the wave is 340 m/s.

When there is a reflection, the wave doubles its distance. In other words, the distance traveled by the sound wave in 1 second is equivalent to  170 meters down to the canyon wall plus 170 meters back from the canyon wall.

Thus, the speed of the wave is 340 m/s.

Find more information about the Speed of waves here:

brainly.com/question/13867834

Answer:

final velocity = 3504 m/s  

Explanation:

Given data:

velocity of missile = Vi = 1350m/s

angle at which missile is moving = 25degree

distance between missile and targets = 23500m

angle between target and missile=55degree

time=10.2s

To find:

Final velocity: ?

Formula:

x = Vx*t + ½*ax*t²  

Let x be the horizontal component of distance

x = ertical component of distance

t-time

ax = horizontal component of acceleration

ay = Vertical component of acceleration

Vx = horizontal component of velocity

Vy = Vertical component of velocity

Solution:

x = Vx*t + ½*ax*t²

23500m * cos55.0º = 1350m/s * cos25.0º * 10.20s + ½ * ax * (10.20s)²  

ax = 19.2 m/s²  

V'x = Vx + ax*t = 1350m/s * cos25.0º + 19.2m/s² * 10.20s = 1419 m/s  

similarly vertically:

y = Vy*t + ½*ay*t² 

23500m * sin55.0º = 1350m/s * sin25.0º * 10.20s + ½ * ay * (10.20s)²  

ay = 258 m/s²  

V'y = Vy + ay*t

     = 1350m/s * sin25.0º + 258m/s² * 10.20s = 3204 m/s  

V = √(V'x² + V'y²)

   = 3504 m/s