Reto: Aníbal desea construir una carpa de base hexagonal de 1,40 m de altura. El vértice de la base es de 0,80m y la longitud de la arista lateral mide 1,80m. ¿cuanto de tela necesito para cubrir la superficie lateral de la carpa? ¿cuanto de tela necesito para cubrir la base de la pirámide, que es un hexágono regular? Cuál es el volumen de la pirámide? ¿cuál es el área total de la pirámide?

Explanation:

[tex]a = \frac{change \: in \: velocity}{change \: in \: time} [/tex]

[tex]a = \frac{v - u}{t} [/tex]

[tex]v = 7 {ms}^{ - 1} [/tex]

[tex]u = 15 {ms}^{ - 1} [/tex]

[tex]t = 3 \: seconds[/tex]

[tex]a = \frac{7 - 15}{3} [/tex]

[tex]a = \frac{ - 8}{3} [/tex]

[tex]a = - 2.67 \: {ms}^{ - 2} [/tex]

Answer:

Displacement

Explanation:

Displacement is a vector quantity i.e it has both magnitude and direction. The direction is indicated with compass bearing i.e North, South, East or West or you could have North East, North West, South West, South East.

Answer:

  D. 3.0 × 10^-6 m

Explanation:

Wavelength is found by dividing the speed of light by the frequency:

  λ = c/f = (3·10^8 m/s)/(1.0·10^14 Hz) = 3.0·10^-6 m

Answer:

El avión recorrió 45 km en los 180 s.

Explanation:

La relación entre velocidad, distancia y tiempo se da de la siguiente manera;

[tex]Velocidad= \dfrac{Distancia}{Hora}[/tex]

Por lo cual los parámetros dados son los siguientes;

Velocidad = 900 km/h = 250 m / s

Tiempo = 180 s

Estamos obligados a calcular la distancia recorrida

De la ecuación para la velocidad dada arriba, tenemos;

Distancia recorrida = Velocidad pf viaje × Tiempo de viaje

Distancia recorrida = 900 km/h × 180 s = 900

Distancia recorrida = 900 km/h × 1 h/60 min × 1 min/60 s × 180 s = 45 km

Por lo tanto, el avión viajó 45 km en 180 s.

Answer:

I = 2.61 A

Explanation:

It is given that,

Power of a toaster is 300 watts

It is plugged into an outlet with a voltage of 115 volts

We need to find the current in the toaster's circuit.

The electrical power is given by the formula as follows :

P = V I

I is electric current

[tex]I=\dfrac{P}{V}\\\\I=\dfrac{300}{115}\\\\I=2.61\ A[/tex]

So, 2.61 A of current is in the toaster's circuit.

Answer: D.

2.61 amps

Explanation: edmentum

Answer:

d = 57.87 m

Explanation:

It is given that,

Acceleration of car due to applied brake is [tex]-5.4\ m/s^2[/tex]

Its initial speed was 25 m/s

Its final speed was 0 as its comes to rest.

Leat d is the distance covered by the car. It can be calculated using third equation of kinematics as :

[tex]v^2-u^2=2ad\\\\d=\dfrac{v^2-u^2}{2a}\\\\d=\dfrac{0^2-(25)^2}{2\times (-5.4)}\\\\d=57.87\ m[/tex]

So, the distance covered by the car is 57.87 m.

Answer:

d = 57.87 m

Explanation:  have a nice day :)

Answer:

I take the thread and wrap it round the cylinder until it goes round the circumference of the cylinder.

Explanation:

I take the thread and wrap it round the cylinder until it goes round the circumference of the cylinder.

I then cut the thread at this length and extend it out on a table or floor.

I then place the length of the thread along the meter rule and mark of the position of its tip and bottom along the meter rule.

The difference between the bottom and top points is the circumference of the cylinder.

If the thread is longer than the meter rule, i mark off where the the length of the meter rule stops along the thread and then place the meter rule at that point and then mark off where the length of the thread stops.

The circumference of the cylinder is then 1 meter plus the extra measurement along the meter rule.

Answer:

The average force has a magnitude 6524 N due north.

Explanation:

The average net force F = ma where m = mass of car = 1400 kg and a = acceleration.

a = (v - u)/t where u = initial velocity of car = 0 m/s (since it starts from rest)

v = final velocity of car = 27 m/s due north and t = time of motion = 5.8 s

a = (27 m/s - 0 m/s)/5.8 s = 27 m/s ÷ 5.8 s = 4.66 m/s

Since the direction of the velocity change is the direction of the acceleration, the acceleration is 4.66 m/s due north.

The average force, F = ma = 1400 kg × 4.66 m/s = 6524 N

Since the acceleration is due north, the average force takes the direction of the acceleration.

So the direction of the average force is due north

The average force has a magnitude 6524 N due north.

Answer:

Height of the first projectile = 49.98 m

Height of the second projectile = 72.52 m

Explanation:

From the given information;

Two projectiles are thrown from the same point with the velocity of49m/s

First is  projected making an angle  θ with the horizontal

and the second at an angle of 90 - θ.

Thus; for the first height to the horizontal; we have;

[tex]H_1 = \dfrac{v^2 sin^2 \theta}{2g}[/tex]  ----- (1)

the second height in the vertical direction is :

[tex]H_2 = \dfrac{v^2 cos^2 \theta}{2g}[/tex]    -----(2)

However; the second is found to rise 22.5 m higher than the first; so , we have :

[tex]\dfrac{v^2 cos^2 \theta}{2g}= 22.5 + \dfrac{v^2 sin^2 \theta}{2g}[/tex]

Let's recall that :

Cos²θ = 1 - Sin²θ

Replacing it into above equation; we have:

[tex]\dfrac{v^2}{2g} - \dfrac{v^2 sin^2 \theta}{2g}= 22.5 + \dfrac{v^2 sin^2 \theta}{2g}[/tex]

[tex]\dfrac{v^2}{2g} - 22.5 = \dfrac{v^2 sin^2 \theta}{g}[/tex]

[tex]\dfrac{1}{2 } \dfrac{v^2}{g} - 22.5 = \dfrac{v^2 sin^2 \theta}{g}[/tex]

[tex]\dfrac{1}{2 } - \dfrac {9.8 \times 22.5}{(49)^2} = sin^2 \theta[/tex]

[tex]\dfrac{1}{2 } - \dfrac {220.5}{2401} = sin^2 \theta[/tex]

[tex]sin^2 \theta= 0.408[/tex]

From (1);

[tex]H_1 = \dfrac{v^2 sin^2 \theta}{2g}[/tex]

[tex]H_1 = \dfrac{49^2 \times 0.408}{2*9.8}[/tex]

[tex]H_1 = \dfrac{979.608}{19.6}[/tex]

[tex]\mathbf{H_1 =49.98 \ m }[/tex]

Height of the first projectile = 49.98 m

Similarly;

From(2)

[tex]H_2 = \dfrac{v^2 cos^2 \theta}{2g}[/tex]    

[tex]H_2 = \dfrac{v^2 (1-sin^2 \theta)}{2g}[/tex]

[tex]H_2 = \dfrac{49^2 (1-0.408 )}{2 \times 9.8}[/tex]

[tex]H_2 = \dfrac{2401 (0.592 )}{19.6}[/tex]

[tex]H_2 = \dfrac{1421.392}{19.6}[/tex]

[tex]\mathbf{H_2 = 72.52 \ m}[/tex]

Height of the second projectile = 72.52 m

Given that,

Weight = 0.75 N

Acceleration due to gravity = 9.81 m/s²

Density of water = 1 g/ml

We need to calculate the volume of water

Using formula of weight

[tex]W=mg[/tex]

[tex]W=\rho Vg[/tex]

[tex]mg=\rho\times V\times g[/tex]

Where, V = volume

g = acceleration

m = mass

Put the value into the formula

[tex]0.076\times 9.8\times10^3=1\times V\times9.8[/tex]

[tex]V= \dfrac{0.076\times 9.8\times10^3}{1\times9.8}[/tex]

[tex]V=76\ ml[/tex]

Hence, The volume of water is 76 mL.

Answer:

76.5mL

Explanation:

w = mg

0.75N = m * 9.81

m = 0.75 / 9.81 = 0.0765 kg

The mass in grams is 0.0765 * 1000 = 76.5g

At a density of 1 g/mL,

76.5g ÷ 1g/ml = 76.5mL

Answer:

20.5m/s

Explanation:

neglecting friction the amount of energy at the bottom equals to the amount of energy at top. Law of conservation of energy.

ME= P.E+k.E

ME= mgh+ 1/2mv*v

ME = (m* 10 *49)+(1/2m(4.6*4.6))

MEtop=500.98m

MEbottom=MEtop: in order to obey the law of conservation of energy

MEbottom=mgh+ 1/2mv*v

500.98m=m*10*29+1/2m v* v

500.98m= m(290+1/2v*v) ...cancel m by m

500.98-290=1/2v*v criss cross multiple

210.98*2=v*v

v=√421.96

v=20.5 m/s

Answer:

The velocity of the marble relative to the water is 3.63 m/s

Explanation:

The information given are;

The velocity of the ferry relative to the water = 3.5 m/s

Direction of motion of the ferry = East

The velocity of the marble (on the ferry) relative to the ferry = 0.95 m/s

The direction of the marble = North

The (resultant) velocity of the marble relative to the water, [tex]v_R[/tex], is found as follows;

Resolution of the velocities;

Velocity of the ferry = 3.5·i + 0·j

Velocity of the marble = 0·i + 0.95·j

[tex]v_R[/tex] = Combined (resultant) velocity = √(3.5² + 0.95²) = 3.63 m/s

The velocity of the marble relative to the water = 3.63 m/s.

Answer:

4.24 km/h

Explanation:

When the man walks at a rate of 3 km/h, the rain appears to fall vertically, which means it has the same horizontal rate, 3 km/h.

When the man walks at a rate of 6 km/h, the rain's horizontal velocity relative to the man is now 6 km/h − 3 km/h = 3 km/h.  The rain meets the man at a 45 degree angle, so the vertical velocity is also 3 km/h.

Therefore, the total speed is:

v = √((3 km/h)² + (3 km/h)²)

v = 4.24 km/h

Answer:

4.489 m/s

Explanation:

We are given;

Length of rod;L = 51.4 cm = 0.514 m

When the ball is at the top end, it's velocity will be zero and it's kinetic energy will be transformed to potential energy.

Thus; ½mv² = mgh

m will cancel out to give;

v² = 2gh

Where:

g is acceleration due to gravity = 9.8 m/s²

h is the maximum height of the ball which is equal to twice the length of the rod.

Thus, h = 2(0.514) = 1.028 m

v² = 2 × 9.8 × 1.028

v = √20.1488

v = 4.489 m/s

Answer:

1.01 W/m

Explanation:

diameter of the pipe d = 30 mm = 0.03 m

radius of the pipe r = d/2 = 0.015 m

external air temperature Ta = 20 °C

temperature of pipe wall Tw = 150 °C

convection coefficient at outer tube surface h = 11 W/m^2-K

From the above, we assumed that the pipe wall and the oil are in thermal equilibrium.

area of the pipe per unit length A = [tex]\pi r ^{2}[/tex] = [tex]7.069*10^{-4}[/tex] m^2/m

convectional heat loss Q = Ah(Tw - Ta)

Q = 7.069 x 10^-4 x 11 x (150 - 20)

Q = 7.069 x 10^-4 x 11 x 130 = 1.01 W/m

The heat loss per unit length of tube should be considered as the 1.01 W/m.

Since

diameter of the pipe d = 30 mm = 0.03 m

radius of the pipe r = d/2 = 0.015 m

external air temperature Ta = 20 °C

temperature of pipe wall Tw = 150 °C

convection coefficient at outer tube surface h = 11 W/m^2-K

Now

area of the pipe per unit length A should be

= πr^2

 = 7.069*10^-4 m^2/m

Now

convectional heat loss Q = Ah(Tw - Ta)

Q = 7.069 x 10^-4 x 11 x (150 - 20)

Q = 7.069 x 10^-4 x 11 x 130

= 1.01 W/m

hence, The heat loss per unit length of tube should be considered as the 1.01 W/m.

Learn more about heat here: https://brainly.com/question/15170783

Answer:

The temperature at the top is -39.5 degree

Explanation:

The height of Mt Everest = 8850 m

The base is at the elevation of = 5400 m

The drop in temperature = 1 degree per 100 m

At the base, the temperature = -5

Since every 100 meter rise in height results in the one degree drop of temperature. Therefore, first find the difference between the base and height. Multiply with negative one.

Difference in heights = 8850 – 5400 = 3450

The temperature at the top = (3450 / 100) + 5 = -39.5 degree

Since there is fall in temperature so we use negative sign.

Answer:

86.17m/s

Explanation:

Since the motion is of constant acceleration, we can use one of the equations of motion as follows;

v² = u² + 2as

Where;

v = final velocity of the airplane

u = initial velocity of the airplane

s = distance covered by the plane

a = acceleration

From the question,

u = 15m/s

s = 600m

a = 6m/s²

Substitute these values into the equation above as follows;

v² = 15² + 2(6)(600)

v² = 225 + 7200

v² = 7425

v = √7425

v  = 86.17m/s

Therefore, the final velocity of the airplane is 86.17m/s

Answer:

n = 3.1x10¹²

Explanation:

To find the number of electrons we need to find first the charge (q):

[tex] I = \frac{q}{\Delta t} \rightarrow q = I*\Delta t [/tex]    (1)

Where:

I: is the electric current = 0.59 A

t: is the time

The time t is equal to:

[tex]v = \frac{\Delta x}{\Delta t} \rightarrow \Delta t = \frac{\Delta x}{v}[/tex]   (2)

Where:

x: is the displacement

v: is the average speed = 2.998x10⁸ m/s

The displacement is equal to the perimeter of the circumference:

[tex] \Delta x = 2\pi*r = \pi*d [/tex]     (3)

Where d is the diameter = 80.0 m

By entering equations (2) and (3) into (1) we have:

[tex]q = I*\Delta t = I*\frac{\Delta x}{v} = \frac{I\pi d}{v} = \frac{0.59 A*\pi*80.0 m}{2.99 \cdot 10^{8} m/s} = 4.96 \cdot 10^{-7} C[/tex]      

Now, the number of electrons (n) is given by:

[tex] n = \frac{q}{e} [/tex]

Where e is the electron's charge = 1.6x10⁻¹⁹ C  

[tex] n = \frac{q}{e} = \frac{4.96 \cdot 10^{-7} C}{1.6 \cdot 10^{-19} C} = 3.1 \cdot 10^{12} [/tex]

Therefore, the number of electrons in the beam is 3.1x10¹².

I hope it helps you!

Light bends away from the normal, because it's moving from higher to lower refractive index.

Same bend-direction as when it goes from water into air.

Answer:

Joule

Explanation:

As any unit of energy (kinetic, potential, etc.), the gravitational potential energy has SI units of Joule. This s the work done by a force of 1 Newton to displace an object 1 meter in the direction of application of the force.

Answer:

i took g = 9.8m/s

A. 1.16secs

B. 2.32secs

C. 6.57m

D. 57.91m

Explanation:

A. How long does the Missile take to reach ot peak?

Time taken (t) =( U²Sin (angle) )/g

u = initial velocity = 25m/s

angle given = 30°

g = acceleration due to gravity = 9.8m/s²

t = U² x Sin (angle) / g

t = 25² x Sin(30)/9.8

t = 1.61secs

B. How long is the missile in the air in total?

T = 2t

T = 2 x 1.61 = 2.32 secs

C. what maximum Height does the missile reach?

D. How far does the missile travel Horizontally?

Answer:

decrease

Explanation:

as the mass of the cart increase the acceleration of the cart decrease

Answer: The final Velocity, V, of the car is 7.9m/s

Explanation:

Given the following :

Toy car starts from rest, therefore,

Initial Velocity (u) = 0

Acceleration (a) = 1.5m/s^2 E for time, t = 5.25s

Final velocity (V) of the car =?

Using the motion equation:

v = u + at

Where v = final Velocity

u = Initial Velocity

a = acceleration

t = time

v = 0 + 1.5(5.25)

v = 0 + 7.875

v = 7.875m/s

v = 7.9m/s

Answer:

By nuclear fission

Explanation:

The sun generates enormous energy through the process of nuclear fusion.

The core or the innermost part of the sun is characterized by high temperature and pressure. These two factors cause the separation of nuclei from electrons and the fusion of hydrogen nuclei to form a  helium atom.

During the fusion process, energy is released.

Answer:

La fuerza promedio que ejerce la resistencia del aire sobre el planeador cuando ingresa con un ángulo de planeo constante de 12 ° con respecto a la Tierra es 9613.8 N

Explanation:

Los parámetros dados son;

Masa del planeador = 980 kg.

Velocidad de lanzamiento horizontal = 480 km / h

Altitud de lanzamiento = 3500 m.

Velocidad de aterrizaje final = 210 km / h

Ángulo de deslizamiento, θ = 12 °

La ecuación para el equilibrio de fuerzas.

L · cos (θ) + D · sin (θ) = W

L · sin (θ) + D · cos (θ)

Dónde:

L = fuerza de elevación

D = fuerza de arrastre

W = Peso del "planeador"

W = Masa del "planeador" × Aceleración debido a la gravedad = 980 kg × 9.81 m / s²

W = 9613.8 N

Por lo tanto, tenemos;

L · cos (12) + D · sin (12) = 9613.8 ,,,,,,,,,,,,, (1)

L · sin (12) = D · cos (12) ,,,,,,,,,,,,, (2)

De la ecuación (2), tenemos;

L = D · (cos (12)/sin (12))

Sustituyendo el valor de L = D · (cos (12) / sin (12)) en la ecuación (1), se obtiene;

D · (cos (12)/sin (12)) · cos (12) + D · sin (12) = 9613.8

D = 9613.8/((cos (12)/sin (12)) · cos (12) + sin (12)) = 1998.82 N

L = D · (cos (12)/sin (12)) = 1998.82 · (cos (12)/sin (12)) = 9403.72 N

Por lo tanto, la fuerza da la fuerza promedio que la resistencia del aire ejerce sobre el planeador cuando ingresa con un ángulo de planeo constante de 12 ° con respecto a la Tierra;

F = √ (L² + D²) = √ (9403.72² + 1998.82²) = 9613.8 N.

Explanation:

If Team A is on the left, B is on the right

if the force is constant, it means that the effort applied is equal.

So Team B is pulling 5000N to the right.

Copper is a reddish orange, soft metal with a bright metallic luster. It is an excellent conductor of heat and electricity. Copper surfaces when exposed to air gradually turns to a dull, brownish color.

Answer:

A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.

Explanation:

In Physics, Doppler effect can be defined as the change in frequency of a wave with respect to an observer in motion and moving relative to the source of the wave.

Simply stated, Doppler effect is the change in wave frequency as a result of the relative motion existing between a wave source and its observer.

The term "Doppler effect" was named after an Austrian mathematician and physicist known as Christian Johann Doppler while studying the starlight in relation to the movement of stars.

The phenomenon of Doppler effects is generally applicable to both sound and light.

An example of the Doppler effect is a police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase. This is so because when a sound object moves towards you, its sound waves frequency increases, thereby causing a higher pitch. However, if the sound object is moving away from the observer, it's sound waves frequency decreases and thus resulting in a lower pitch.

Other fields were the Doppler effects are applied are; astronomy, flow management, vibration measurement, radars, satellite communications etc.

Answer:

A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.

Explanation:

This should be the correct answer.

Answer:

C

Explanation:

It is directly propotional to the amount of charge and inversly propotional to distance.

Answer:

C. Distance and amount of charge

Explanation:

The magnitude of the electric potential depends on which factors?

Distance and amount of charge

Answer:

1120 N

Explanation:

The velocity with which he hits the water can be found with kinematics:

v² = v₀² + 2aΔy

v² = (0 m/s)² + 2 (-9.8 m/s²) (-9.00 m)

v = -13.3 m/s

Or it can be found with conservation of energy.

PE = KE

mgh = ½ mv²

v = √(2gh)

v = √(2 × -9.8 m/s² × -9.00 m)

v = -13.3 m/s

Sum of forces on the diver after he hits the water:

∑F = ma

F − mg = m Δv/Δt

F − (74.0 kg) (9.8 m/s²) = (74.0 kg) (0 m/s − (-13.3 m/s)) / (2.50 s)

F = 1120 N