Static electricity is the build up of an electrical charge on the surface of an
object. Why is it called "static" electricity?*

Answer:

0.25 kg

Explanation:

p = mv

2 = m(8)

2/8 = m(8)/8 *cancels

m = 1/4 OR 0.25 kg

Answer:

Explanation:

hormones. please mark me brainliest

Answer:

TRUE

Explanation:

IM SMART

Answer:

Stay  Safe! ,God bless you . The answer is false ,

Explanation:

Answer:

t = 3 [s]

Explanation:

To solve this problem we must use the following equation of kinematics.

[tex]v_{f}=v_{o}-g*t[/tex]

where:

Vf = final velocity [m/s]

Vo = initial velocity = 15 [m/s]

g = gravity acceleration = 10 [m/s²]

t = time [s]

Now replacing we have:

[tex]0 = 15 -10*t\\10*t=15\\t= 1.5[s][/tex]

Note: In the equation above the gravity acceleration is negative, because the movement of the ball bearing is pointing againts the gravity acceleration.

The time calculated is only when the ball bearing reaches the highest elevation, and it will take the same time for descending, therefore the total time is:

t = 1.5 + 1.5 = 3 [s]

Answer:

Its A. door because liquids expand better than solids

Answer: C. Africa

Explanation:

The data given on the graph shows that:

Asia will grow from around 1,300 million to 5,000 million in 2050 which is an increase of:

= 5,000 /1,300 = 3.84 times

Europe will decrease over that period.

Africa will go from around 300 million to 2,000 million which is an increase of:

= 2,000 / 300

= 6.67 times

Mexico

, Central America, Caribbean Islands:

= 900 / 120

= 7.5 times

United States,  Canada, and Greenland:

= 400/120

= 3.33

Oceania:

= 50 / 13

= 3.85

From the options give, Africa will see the greatest increase at 6.67 times its population in 1950.

Answer:

Explanation:

From the given information;

Let assume that:

the wheel radius = 15 inches

the driveline slippage = 3%;  &

the gear reduction ratio (overall) = 2.5 to 1

So; using the equation:

[tex]v_1= \dfrac{2 \pi r n_o (1 -i)}{\varepsilon_o}[/tex]

[tex]v_1= \dfrac{2 \times 3.14 \times \dfrac{15}{12} \times \dfrac{85}{100} (1 -0.03)}{2.5}[/tex]

[tex]v_1= \dfrac{2 \times 3.14 \times \dfrac{15}{12} \times \dfrac{85}{100} (0.97)}{2.5}[/tex]

[tex]v_1 = 126.92 \ fp^3[/tex]

[tex]frl = 0.01 ( 1+ \dfrac{v}{147}) \ if \ v \ is \ ft/sec[/tex]

[tex]frl = 0.01 \Bigg( 1+ \dfrac{\dfrac{126.92 +(20)1.47 }{2} }{147}\Bigg)[/tex]

[tex]S = \dfrac{v_b ( v_1^r-v_2^r)}{2g(n_b \mu + frl \pm sin \ y}[/tex]

where;

[tex]\mu = 0.6[/tex]

[tex]291 = \dfrac{1.64( 126.92^2-29.9^2)}{64.4(n_b \times 0.6 +0.01532 +0.03}[/tex]

[tex]n_b = 1.33 \to which \ is \ not \ possible[/tex]

However;

[tex]n_b \mu = 1.33(0.6) = 0.80[/tex]

[tex]\mu = 0.9 \to[/tex] if the car's anti-clock breaking system did not fail

Thus;

[tex]n_b (0.9) = 0.80[/tex]

[tex]n_b =\dfrac{ 0.80}{(0.9) }[/tex]

[tex]n_b = 0.89[/tex]

Hence, the distance is possible if the anti-clock breaking system did not fail.

Answer:

1.007 kg/m³

Explanation:

Given that:

volume = 2500 m³

density of air [tex]\rho = 1.23 \ kg/m^3[/tex]

weight of air displaced = [tex]V \times \rho \times g[/tex]

= 2500 × 1.23 × 9.81

= 30165.75 N

weight of the ballon fabric = 860 N; &

The propane weight = 1200 N

The passenger additional weight = 3400 N

weight of the heated gas will be = V × d × g

= 2500 × d  9.81

= 24525 d

For floating

The weight of air displaced is less than 30165.75

∴ 860 + 1200 + 3400 + 24525 d = 30165.75

5460 + 24525 d = 30165.75

24525 d = 24705.75

d = 24705.75  / 24525

d = 1.007 kg/m³

Hence, the average density of the heated gas = 1.007 kg/m³

Answer:

The wagon will move to the right.

Explanation:

From the question given above, the following data were obtained:

Force applied to the left (Fₗ) = 10 N

Force applied to the right (Fᵣ) = 30 N

Direction of the wagon =.?

To determine the direction in which the wagon will move, we shall determine the net force acting on the wagon. This can be obtained as follow:

Force applied to the left (Fₗ) = 10 N

Force applied to the right (Fᵣ) = 30 N

Net force (Fₙ) =?

Fₙ = Fᵣ – Fₗ

Fₙ = 30 – 10

Fₙ = 20 N to the right

From the calculations made above, the net force acting on the wagon is 20 N to the right. Hence the wagon will move to the right.

Answer:

6692J

Explanation:

Power is defined as the rate at which work is being done.

So,

    Power  = [tex]\frac{workdone}{time }[/tex]  

  Work done  = Power x time

Given parameters:

Power  = 478watts

Time  = 14s

So;

 Work done  = 478 x 14  = 6692J

Answer:  Choice A) 2 meters per second

=======================================================

Explanation:

The smaller ball has momentum of

p = m*v

p = (1 kg)*(4 m/s)

p = 4 kg*m/s

All of this momentum transfers into the larger ball because the smaller ball comes to a complete stop.

For the larger ball, we have p = 4 and m = 2. Let's find v.

p = m*v

4 = 2*v

4/2 = v

2 = v

v = 2 m/s which is why the answer is choice A

The larger ball moves at a speed of 2 meters per second. The speed is cut in half compared to the smaller ball because the larger ball has more inertia (aka more mass), and therefore it takes more energy to move it. If you apply the same energy to each, then the smaller object moves faster.

Answer:

Magnetism is caused by the motion of electric charges. Every substance is made up of tiny units called atoms. Each atom has electrons, particles that carry electric charges. ... Their movement generates an electric current and causes each electron to act like a microscopic magnet.

Explanation:

Answer:

a) The force of static friction the road can apply before the car starts to move is 8826.3 newtons.

b) The maximum speed that a car can travel before it would start to slide is approximately 34.305 meters per second.

Explanation:

a) Let suppose that the car is on a horizontal ground and travels at constant speed. The vehicle experiments a centripetal acceleration due to friction, which can be seen in the Free Body Diagram (please see image attached for further details). By Newton's Laws, we construct the following equations of equilibrium:

[tex]\Sigma F_{x} = \mu_{s}\cdot N = m\cdot \frac{v^{2}}{R}[/tex] (1)

[tex]\Sigma F_{y} = N -m\cdot g = 0[/tex] (2)

Where:

[tex]\mu_{s}[/tex] - Static coefficient of friction, dimensionless.

[tex]N[/tex] - Normal force from ground to the car, measured in newtons.

[tex]v[/tex] - Maximum speed of the car, measured in meters per second.

[tex]R[/tex] - Radius of the circular track, measured in meters.

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

[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.

By applying (2) in (1):

[tex]\mu_{s}\cdot m\cdot g = m\cdot \frac{v^{2}}{R}[/tex] (3)

The force of static friction the road can apply in the car ([tex]f[/tex]), measured in newtons, is: ([tex]\mu_{s} = 0.6[/tex], [tex]m = 1500\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex])

[tex]f = \mu_{s}\cdot m \cdot g[/tex]

[tex]f = (0.6)\cdot (1500\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)[/tex]

[tex]f = 8826.3\,N[/tex]

The force of static friction the road can apply before the car starts to move is 8826.3 newtons.

b) Then, we calculate the maximum speed of the car by (3):

[tex]\mu_{s}\cdot m\cdot g = m\cdot \frac{v^{2}}{R}[/tex]

[tex]\mu_{s}\cdot g = \frac{v^{2}}{R}[/tex]

[tex]v = \sqrt{\mu_{s}\cdot g\cdot R}[/tex]

If we know that [tex]\mu_{s} = 0.6[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]R = 200\,m[/tex], then the maximum speed of the car can travel before it would start to slide is:

[tex]v =\sqrt{(0.6)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (200\,m)}[/tex]

[tex]v \approx 34.305\,\frac{m}{s}[/tex]

The maximum speed that a car can travel before it would start to slide is approximately 34.305 meters per second.

Answer:

a. F = 245 Newton.

b. Workdone = 392 Joules.

c. Power = 196 Watts

Explanation:

Given the following data;

Mass = 25kg

Distance = 1.6m

Time = 2secs

a. To find the force needed to lift the mass (in N );

Force = mass * acceleration

We know that acceleration due to gravity is equal to 9.8

F = 25*9.8

F = 245N

b. To find the work done by the student (in J);

Workdone = force * distance

Workdone = 245 * 1.6

Workdone = 392 Joules.

c. To find the power exerted by the student (in W);

Power = workdone/time

Power = 392/2

Power = 196 Watts.

Answer:

Explanation:

Average energy contained by  a slice of pizza is 860 J  .

energy used in lifting 32 kg bar by .50 m = mgh

= 32 x 9.8 x .5 = 156.8 J

efficiency is 25 % , so energy used up = .75 x 156.8 = 117.6 J

So number of times exercise to be repeated to burn off energy of a slice of pizza

= 860 / 117.6

= 7.3 or 7 times .

Answer:

15 seconds

Explanation:

If car was moving at 20m/s for 3 sec.

if car traveled 100m = 15 sec total

Answer:

Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle's convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.

Explanation:

eventually the crust cracks.

Answer:

the answer is B

Explanation:

I think its B because on the top it shows the molecule speed and A looks like the water is cold, C shows that the hot

water is cooler, and D shows that both are cold

Answer:

The required frequency = 0.442 Hz

Explanation:

Frequency [tex]f = ( \dfrac{1}{2 \pi}) \omega[/tex]

where;

[tex]\omega = \sqrt{\dfrac{k}{m} }[/tex]

Then;

[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{k}{m} } \Bigg )[/tex]

However;

[tex]k = \dfrac{F}{x}[/tex] and;

mass [tex]m = m_{car } + m_{person}[/tex]

[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{\dfrac{F}{x}}{m_{car}+m_{person}} } \Bigg )[/tex]

[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{{F}}{x(m_{car}+m_{person})} } \Bigg )[/tex]

where;

[tex]F = m_{person}g[/tex]

Then;

[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{ {m_{person}g }}{x(m_{car}+m_{person})} } \Bigg )[/tex]

replacing the values;

[tex]f = \Bigg ( \dfrac{1}{2 \pi} \Bigg ) \Bigg( \sqrt{\dfrac{ {(88 \ kg)* (9.81 \ m/s^2) }}{(5.36 \times 10^{-2} \ m) (2002 \ kg +88 \ kg)} } \Bigg )[/tex]

[tex]\mathbf{f = 0.442 \ Hz}[/tex]

Answer:

[tex]500 \: \mathrm{kg} \cdot \mathrm{m/s}[/tex]

Explanation:

The momentum of an object is given as [tex]p=mv[/tex]. Since Amy has a mass of 50 kg and is travelling 10 m/s, her momentum is [tex]p=mv=50\cdot 10 =\fbox{$500\: \mathrm{kg\cdot m/s}$}[/tex].

Answer:

500

Explanation:

Answer:

The rotation frequency required is 23.78 RPM

Explanation:

Given;

radial acceleration, a = 32.7 m/s²

length of the beam, r = 5.29 m

The linear velocity is calculated as;

[tex]a = \frac{v^2}{r} \\\\v^2 = ar\\\\v = \sqrt{ar}[/tex]

where;

v is linear velocity

The angular velocity is calculated as;

[tex]\omega = \frac{v}{r} \\\\Recall, v = \sqrt{ar} \\\\Then, \omega = \frac{\sqrt{ar}}{r}} \\\\ \omega = \frac{\sqrt{32.7 \times5.29}}{5.29}\\\\\omega = 2.49 \ rad/s\\\\Angular \ frequency \ is \ calculated \ as;\\\\\omega = 2\pi f\\\\f = \frac{\omega}{2\pi} \\\\f = \frac{2.49}{2\pi} \\\\f = 0.396 \ rev/s\\\\f = 23.78 \ rev/min[/tex]

Therefore, the rotation frequency required is 23.78 RPM

Answer:

The contributions of the following scientist in the DEVELOPMENT OF MAGNETIC THEORY

Explanation:

George Green was the first personality to formulate a mathematical principle of magnetism and electricity and his system created the framework for the work of different scientists such as William Thomson, James Clerk Maxwell, and others. Magnetism is the power exercised by magnets when they drag or deflect each other. Magnetism is produced by the movement of electric charges.

The contributions of James Clerk Maxwell  and Hans Christian Oersted, et al in the DEVELOPMENT OF MAGNETIC THEORY are as follows:

According to the given question, we are asked to show the contributions which the aforementioned scientists had in the development of the magnetic theory.

As a result of this, we can see that James Maxwell first developed this theory in the nineteenth century and the theory was modified by other scientists who made the framework for the electrical system and magnetism.

Read more here:

https://brainly.com/question/17913237

Answer:

California has one of the most variable climates of any U.S state, and often experiences very wet years followed by extremely dry ones . The state's reservoirs have insufficient capacity to balance the water supply between wet and dry years.

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Answer:

A) 8,368 J

B) ) 0.893 J/gºC

Explanation:

A)

       [tex]q_{g} = c_{w} * m * \Delta T (1)[/tex]

       [tex]q_{g} = c_{w} * m * \Delta T = 4.184 J/gºC*1,000 g* 2ºC = 8,368 J (2)[/tex]

B)

       [tex]q_{l} = c_{Al} * m_{Al} * \Delta T (3)[/tex]

⇒    [tex]-8,368 J = c_{Al}* 125 g * (-74.95ºC) (4)[/tex]

       [tex]c_{Al} = \frac{-8,368J}{125g*(-74.95ºC} = 0.893 J/gºC (5)[/tex]