How long is a WiFi wavelength? A) 10 cm B) 12 cm C) 15 cm D) 20cm

When a 25000-kg fighter airplane lands on the deck of the aircraft carrier, the carrier sinks 0.23cm deeper into the water.

Genrish500 [490]

Answer:

10604 square meters

Explanation:

0.23 cm = 0.0023m

Assume the carrier has a shape of a rectangular box. When the carrier sinks 0.0023m deeper into water, the extra volume submerged into water is the same as the extra water volume being replaced. This extra volume would add an additional buoyant force to counter balance the extra weight created by the 25000 kg fighter.

With g being constant, the mass of the extra water displaced is the same as the mass of the fighter airplane $m_f$ . And mass of the water displaced is its volume V times its density $\rho$

$V\rho = m_f$

$1025V = 25000$

$V = 25000/1025 = 24.39 m^3$

We assume the carrier has a shape of a rectangular box, so this extra displaced volume is the extra depth d = 0.0023 m times cross-section area A

$V = dA$

$24.39 = 0.0023A$

$A = 24.39 / 0.0023 = 10604 m^2$

4 0

4 years ago

Why does a tail appear when a comet nears the sun?

ahrayia [7]

It heats up. the ice transforms directly from a solid to a vapor, releasing dust particles. the solar wind sweeps the material and it forms what to appears to be a tail.

3 0

4 years ago

A weightlifter completes a series of lifts with a 700 N weight. In one lift, he raises the weight to a height of 2.5 m off the g

zhannawk [14.2K]

Answer:

The output power the weightlifter is 2916.67 W.

Explanation:

Given;

weight lifted, W = 700 N

height the weight is lifted, h = 2.5 m

time taken to lift the weight, t = 0.60 s

The output power the weightlifter is calculated as;

Power = Energy applied / time taken

Energy applied = weight lifted x height the weight is lifted

Energy applied = 700 x 2.5

Energy applied = 1750 J

Power = 1750 / 0.6

Power = 2916.67 J/s = 2916.67 W.

Therefore, the output power the weightlifter is 2916.67 W.

5 0

3 years ago

A 0.37-kg object connected to a light spring with a force constant of 23.2 N/m oscillates on a frictionless horizontal surface.

mars1129 [50]

Answer:

a) v = 31.67 cm / s , b) v = -29.36 cm / s , c) v= 29.36 cm/s, d) x = 3.46 cm

Explanation:

The angular velocity in a simple harmonic movement is

w = √ K / m

w = √ 23.2 / 0.37

w = 7,918 rad / s

a) the expression against the movement is

x = A cos (wt + Ф)

Speed is

v = dx / dt = - A w sin (wt + Ф)

The maximum speed occurs for cos = ± 1

v = A w

v = 4.0 7,918

v = 31.67 cm / s

b) as the object is released from rest

0 = -A w sin (0+ Фi)

sin Ф = 0

Ф = 0

The equation is

x = 4.0 cos (7,918 t)

v = -4.0 7,918 sin (7,918 t)

v = - 31.67 sin (7.918t)

Let's look for the time for a displacement of x = 1.5 cm, remember that the angles must be in radians

7,918 t = cos⁻¹ 1.5 / 4.0

t = 1,186 / 7,918

t = 0.1498 s

We look for speed

v = -31.67 sin (7,918 0.1498)

v = -29.36 cm / s

c) if the object passes the equilibrium equilibrium position again at this point the velocity has the same module, but the opposite sign

v = 29.36 cm / s

d) let's look for the time for the condition v = v_max / 2

31.67 / 2 = 31.67 sin ( 7,918 t)

7.918t = sin⁻¹ 0.5

t = 0.5236 / 7.918

t = 0.06613

With this time let's look for displacement

x = 4.0 cos (7,918 0.06613)

x = 3.46 cm

6 0

3 years ago

The pan flute is a musical instrument consisting of a number of closed-end tubes of different lengths. When the musician blows o

IgorLugansk [536]

Answer:

f = 276.6 Hz

Explanation:

This musical instrument can be approximated to a tube system where each tube has one end open and the other closed.

In the closed part there is a node and in the open part a belly or antinode. Therefore the wavelength is

L = λ/ 4

speed is related to wavelength and frequency

v = λ f

λ = v / f

we substitute

L = v / 4f

f = v / 4L

the speed of sound at 20ºC is

v = 343 m / s

let's calculate

f = $\frac{343 }{4 \ 0.31}$

f = 276.6 Hz

4 0

3 years ago