I dont understand physics.

Answer:

280N

Explanation:

As the statement put in parenthesis state-You need to add up all the forces acting on the object to find the net force, so over here-

250+30=280N

Answer:

True  b and c

Explanation:

In an RLC circuit the impedance is

         [tex]Z = \sqrt{[R^{2} + ( (wL)^{2} + (\frac{1}{wC})^{2} ] }[/tex]

examine the different phrases..

a) False. The maximum impedance is the value of the resistance  

b) True. Resonance occurs when  

              (wL)² + (1 / wC)² = 0

               w² = 1 / LC

c) True. In resonance the impedance is the resistive part and the power is maximum  

d) False. In resonance the inductive and capacitive part cancel each other out  

e) False. The impedance is always greater outside of resonance, but at the resonance point they are equal

Answer:

Answer b)

Explanation:

The correct answer is that analog technology stores information as sound-waves, while digital technology stores it as strings of ones and zeroes. So pick answer b)

Answer:

here u go

Explanation:

Earth's rotation is the rotation of planet Earth around its own axis. Earth rotates eastward, in prograde motion. As viewed from the north pole star Polaris, Earth turns counterclockwise.

Answer:

C. Some of the mass of the four hydrogen nuclei was converted into

energy

Explanation:

a p e x , just took the quiz

Some of the mass of the four hydrogen nuclei was converted into energy.

When four hydrogen nuclei fuse to form one helium nuclei, mass defect, some mass is converted into energy, that is the reason of energy of the sun.

"When two nuclei form a big nuclei, the phenomenon is known as fusion."

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Answer:

A stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following best describes why no injury occurs?

The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.

ANSWER: A

Answer:

A. The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.

During stunts, people usually put an-air filled bag on the ground for safe landing and to prevent injuries.

Momentum is calculated by m* v where m is for mass and v is for velocity.

Force is directly proportional to momentum

F∝M

The bag in this scenario helps to increases the amount of time the force acts on the person. This implication means that there is a reduction in the change of momentum. Since Force and momentum have a directly proportional relationship then the Force taken to hit the floor is greatly reduced.

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Answer:

C.

Explanation:

There is such thing a wave energy, but that doesn't quite fit for this question. B. I have not heard of that, so it has to be incorrect. C.  Yes, energy can cause motion in a lot of ways. D. Energy can change forms so that is incorrect.

Answer:

The apparent fit of the eastern coastline of South America and western coastline of Africa

Similarities of plants and animal fossils in South America and some parts of African continent which were separated by a vast ocean

Similarities in the sequence of rock layers of opposite sides of the Atlantic Ocean

Answer:

E_{pot} = 132.3 [J]

Explanation:

In order to solve this problem, we must use the definition of the potential energy which can be calculated by means of the following formula.

[tex]E_{pot}=W*h[/tex]

where:

Epot = potential energy [J]

W = weight = 5.4 [N]

h = elevation = 24.5 [m]

[tex]E_{pot}=5.4*24.5\\E_{pot}=132.3[J][/tex]

Answer:

a) The velocity when it passes the equilibrium point is [tex]\pm 2.451[/tex] meters per second.

b) The velocity when it is 0.10 meters from equilibrium is [tex]\pm 1.567[/tex] meters per second.

c) The total energy of the system is 1.802 joules.

d) The equation describing the motion of the mass, assuming that initial position is a maximum is [tex]x(t) = 0.13\cdot \sin (18.850\cdot t +0.5\pi)[/tex].

Explanation:

a) If all non-conservative forces can be neglected and spring has no mass, then the mass-spring system exhibits a simple harmonic motion (SHM). The kinematic formula for the position of the system ([tex]x(t)[/tex]), measured in meters, is:

[tex]x(t) = A\cdot \sin(\omega \cdot t +\phi)[/tex] (1)

Where:

[tex]A[/tex] - Amplitude, measured in meters.

[tex]\omega[/tex] - Angular frequency, measured in radians per second.

[tex]t[/tex] - Time, measured in seconds.

[tex]\phi[/tex] - Phase, measured in radians.

The kinematic equation for the velocity formula of the system ([tex]v(t)[/tex]), measured in meters per second, is derived from (1) by deriving it in time:

[tex]v(t) = \omega\cdot A\cdot \cos (\omega\cdot t+\phi)[/tex] (2)

The velocity when it passes the equilibrium point occurs when the cosine function is equal to 1 or -1. Then, that velocity is determined by following formula:

[tex]v = \pm \omega\cdot A[/tex] (3)

The angular frequency is calculated by this expression:

[tex]\omega = 2\pi\cdot f[/tex] (4)

Where [tex]f[/tex] is the frequency, measured in hertz.

If we know that [tex]f = 3\,hz[/tex] and [tex]A = 0.13\,m[/tex], then the velocity when it passes the equilibrium point, which is the maximum and minimum velocities of the mass:

[tex]\omega = 2\pi\cdot (3\,hz)[/tex]

[tex]\omega \approx 18.850\,\frac{rad}{s}[/tex]

[tex]v = \pm \left(18.850\,\frac{rad}{s} \right)\cdot (0.13\,m)[/tex]

[tex]v = \pm 2.451\,\frac{m}{s}[/tex]

The velocity when it passes the equilibrium point is [tex]\pm 2.451[/tex] meters per second.

b) First, we need to determine the spring constant of the system ([tex]k[/tex]), measured in newtons per meter, in terms of the angular frequency ([tex]\omega[/tex]), measured in radians per second, and mass ([tex]m[/tex]), measured in kilograms. That is:

[tex]k = \omega^{2}\cdot m[/tex] (5)

If we know that [tex]\omega \approx 18.850\,\frac{rad}{s}[/tex] and [tex]m = 0.60\,kg[/tex], then the spring constant is:

[tex]k = \left(18.850\,\frac{rad}{s} \right)^{2}\cdot (0.60\,kg)[/tex]

[tex]k = 213.194\,\frac{N}{m}[/tex]

Lastly, we determine the velocity when the mass is 0.10 meters from equilibrium by the Principle of Energy Conservation:

[tex]U_{k} + K = K_{max}[/tex] (6)

[tex]\frac{1}{2}\cdot k\cdot x^{2} + \frac{1}{2}\cdot m\cdot v^{2} = \frac{1}{2}\cdot m\cdot v_{max}^{2}[/tex] (7)

Where:

[tex]U_{k}[/tex] - Current elastic potential energy, measured in joules.

[tex]K[/tex] - Current translational kinetic energy, measured in joules.

[tex]K_{max}[/tex] - Maximum translational kinetic energy, measured in joules.

[tex]v[/tex] - Current velocity of the system, measured in meters per second.

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

[tex]v_{max}[/tex] - Maximum velocity of the system, measured in meters per second.

If we know that [tex]k = 213.194\,\frac{N}{m}[/tex], [tex]x = 0.10\,m[/tex], [tex]m = 0.60\,kg[/tex] and [tex]v_{max} = \pm 2.451\,\frac{m}{s}[/tex], then the velocity of the mass-spring system is:

[tex]\frac{k}{m} \cdot x^{2} + v^{2} = v_{max}^{2}[/tex]

[tex]v^{2} = v_{max}^{2}-\frac{k}{m}\cdot x^{2}[/tex]

[tex]v = \sqrt{v_{max}^{2}-\frac{k\cdot x^{2}}{m} }[/tex] (8)

[tex]v = \sqrt{\left(\pm 2.451\,\frac{m}{s} \right)^{2}-\frac{\left(213.194\,\frac{N}{m} \right)\cdot (0.10\,m)^{2}}{0.60\,kg} }[/tex]

[tex]v \approx \pm 1.567\,\frac{m}{s}[/tex]

The velocity when it is 0.10 meters from equilibrium is [tex]\pm 1.567[/tex] meters per second.

c) The total energy of the system ([tex]E[/tex]), measured in joules, can be determined by the following expression derived from the Principle of Energy Conservation:

[tex]E = \frac{1}{2}\cdot m\cdot v_{max}^{2}[/tex] (9)

If we know that [tex]m = 0.60\,kg[/tex] and [tex]v_{max} = \pm 2.451\,\frac{m}{s}[/tex], then the total energy of the system is:

[tex]E = \frac{1}{2}\cdot (0.60\,kg)\cdot \left(\pm 2.451\,\frac{m}{s}\right)^{2}[/tex]

[tex]E = 1.802\,J[/tex]

The total energy of the system is 1.802 joules.

d) Given that initial position of the mass-spring system is a maximum, then we conclude that the equation of motion has the following parameters: ([tex]A = 0.13\,m[/tex], [tex]\omega \approx 18.850\,\frac{rad}{s}[/tex] and [tex]\phi = 0.5\pi\,rad[/tex])

From (1) we obtain the resulting formula:

[tex]x(t) = 0.13\cdot \sin (18.850\cdot t +0.5\pi)[/tex] (10)

The equation describing the motion of the mass, assuming that initial position is a maximum is [tex]x(t) = 0.13\cdot \sin (18.850\cdot t +0.5\pi)[/tex].

Answer:

protons are in the nucleus .

Explanation:

there are 6 protons

Answer:

The stars were always made of hot gas a million miles away from here

Explanation:

I study stars

Answer:

It enabled them to run faster from predators.

Explanation:

The evolution of hooves from a five-digit feet enabled horses to run faster from predators as well as support their larger weights and longer legs. Hope this helped and have an awesome day! :)

It enabled them to run faster from predators. ]

Explanation: The evolution of hooves from a five-digit feet enabled horses to run faster from predators as well as support their larger weights and longer legs.

Answer:

C. crust, mantle, core

Explanation:

density increases as you travel from the crust to the inner core

the crust is on top

next is the mantle

and then the core

Answer:

C. Crust, mantle, core

Explanation:

If you travel further into the earth's core, the density and pressure increases, along with temperature.

Answer:

The torque on the child is now the same, τ.

Explanation:

       [tex]I_{to} = I_{d} + m*r^{2} = m*\frac{r^{2}}{2} + m*r^{2} = \frac{3}{2}* m*r^{2} (1)[/tex]

       [tex]I_{t} = I_{d} + m*\frac{r^{2}}{4} = m*\frac{r^{2}}{2} + m*\frac{r^{2}}{4} = \frac{3}{4}* m*r^{2} (3)[/tex]

       τ = 3/4*m*r² * (2α) = 3/2*m*r²

        same result than in (2), so the torque remains the same.

Answer:

D.

Explanation

Air pressure.

Answer:air pressure

Explanation:

Answer:

[tex]976562.5\ Joules[/tex]

Explanation:

[tex]We\ are\ given:\\The\ mass\ of\ the\ missile=125\ kg\\The\ velocity\ of\ the\ missile=125\ m/s\\Hence,\\As\ we\ know\ that,\\Kinetic\ energy\ possessed\ by\ an\ object\ with\ mass\ m\ moving\\ with\ a\ velocity\ v:\\E_k=\frac{1}{2}mv^2\\Here,\\The\ Kinetic\ Energy\ possessed\ by\ the\ missile=\frac{1}{2}*125*(125)^2=976562.5\ Joules[/tex]

Answer:

spirit of the team / game

Answer:

Volume =  24 cm^3

Explanation:

We recall that the volume of the box is calculated via the formula:

Volume = length * height * width

and that in a product, the number of significant figures for the result should coincide with the number of significant figures of the factor that has the least of them.

In this case, all measures have the same number of significant figures: two. so we calculate the product, and then limit the answer value to exactly two significant figures:

Volume = 4.1 cm * 2.8 cm * 2.1 cm = 24.108 cm^3, which must be rounded to two significant figures as: 24 cm^3

Answer:

Volume = 24.108cm³

Explanation:

Volume = length × breadth × height

Volume = 4.1 × 2.8 × 2.1

Volume = 24.108

The Box's Acceleration : g sin θ

Newton's 2nd law explains that the acceleration produced by the resultant force on an object is proportional and in line with the resultant force and inversely proportional to the mass of the object  

∑F = m. a  

F = force, N  

m = mass = kg  

a = acceleration due to gravity, m / s²  

We plot the forces acting on the block (picture attached) according to the y-axis and the x-axis.

Because the motion of the block is in the same direction as the x-axis, ignoring the friction force with the inclined plane, then

[tex]\tt \sum F_x=m.a\\\\W.sin\theta=m.a\\\\mgsin\theta=m.a\\\\a=gsin\thet\theta[/tex]

Answer:

a) v = 5.59x10³ m/s

b) T = 4 h

c) F = 1.92x10³ N

Explanation:

a) We can find the satellite's orbital speed by equating the centripetal force and the gravitation force as follows:

[tex] F_{c} = F_{G} [/tex]

[tex]\frac{mv^{2}}{r + h} = \frac{GMm}{(r + h)^{2}}[/tex]

[tex] v = \sqrt{\frac{gr^{2}}{r+h} [/tex]          

Where:

g is the gravity = 9.81 m/s²        

r: is the Earth's radius = 6371 km

h: is the satellite's height = r = 6371 km      

[tex]v = \sqrt{\frac{gr^{2}}{2r}} = \sqrt{\frac{gr}{2}} = \sqrt{\frac{9.81 m/s^{2}*6.371 \cdot 10^{6} m}{2}} = 5.59 \cdot 10^{3} m/s[/tex]                                      

b) The period of its revolution is:

[tex] T = \frac{2\pi}{\omega} = \frac{2\pi (r + h)}{v} = \frac{2\pi (2*6.371 \cdot 10^{6} m)}{5.59 \cdot 10^{3} m/s} = 14322.07 s = 4 h [/tex]

c) The gravitational force acting on it is given by:

[tex] F = \frac{GMm}{(r + h)^{2}} [/tex]

Where:

M is the Earth's mass =  5.97x10²⁴ kg    

m is the satellite's mass = 782 kg

G is the gravitational constant = 6.67x10⁻¹¹ Nm²kg⁻²

[tex] F = \frac{GMm}{(r + h)^{2}} = \frac{6.67 \cdot 10^{-11} Nm^{2}kg^{-2}*5.97 \cdot 10^{24} kg*782 kg}{(2*6.371 \cdot 10^{6} m)^{2}} = 1.92 \cdot 10^{3} N [/tex]

I hope it helps you!

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{2250}{1.4} \\ = 1607.14285...[/tex]

We have the final answer as

Hope this helps you

Answer:

[tex]\boxed{True}[/tex]

Explanation:

Objects are weightless in free fall because their is no other force pushing them rather than the gravitational force.

Hope it helps!<3

Answer:

Explanation:

Answer:

 Fₓ = 123.8 N and     F_{y} = 0

Explanation:

This is a static balance exercise, to see the forces, see the attachment. In this W is the weight of the ladder and W1 the weight of the man.

locate a reference system at the bottom of the ladder with the horizontal x axis, it will assume that the counterclockwise turns are positive

         Σ τ = 0

          x  + Fₓ y - W₁ d₁ -W d₂ + N 0 + fr 0 = 0

   use trigonometry to find the distances

       cos θ = x / L

       θ = cos⁻¹ (x / L)

       θ = cos⁻¹ (2 / 6.82)

       θ = 72.9º

        in 72.9 = y / L

        y = L sin 72.9

        y = 6.82 sin 72.9

        y = 6.519 m

Center of mass ladder

        cos 72.9 = d₂ / 2

        d₂ = 2 cos 72.9 = 0.588 m

x coordinate of man

       cos 72.9 = d₁ / 3

       d₁ = 3 cos 72.9 = 0.882 m

we substitute

      2 + Fₓ 6.519 - W₁ 0.882 -W 0.588 = 0

as they indicate that the plastic basket has no friction

       F_{y} = 0

       Fₓ 6.519 - W₁ 0.882 -W 0.588 = 0

       Fₓ 6.519 = M₁ g 0.882 + m g 0.588

we calculate

         Fₓ = 85 9.8 0.882 + 12.6 9.8 0.588) / 6.519

         Fₓ = 123.8 N

Answer:

[tex]\boxed{\boxed{\sf all \ of \ the \ above }}[/tex]

Good conductors have: current moves easily,  low resistance,   conserves energy-easy for electrons to move. Hence, Option (C) is correct.

Materials that easily permit the flow of electricity are referred to be electrical conductors. Conductivity is the quality of conductors that enables them to conduct electricity.

Electric current is the name given to the movement of electrons through conductor. Voltage is the amount of power necessary to cause that current to flow through the conductor.

Such an element receives a charge that is dispersed along its entire surface, causing the electrons inside the element to migrate. Charges are transferred to an electrical conductor, and they disperse until the minimal force of repulsion between electrons in locations of excess electrons. Such an item transfers its charge to another conductor when it comes into contact with it, reducing the overall repulsion caused by charge in the process.

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