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3 years ago

A radar operates at a wavelength of 3 centimeters. what is the frequency of the these waves? the speed of light is 3 × 108 m/s .

1 answer:

4 0

We are given information:
λ $= wavelength = 3cm = 0.03m \\ 
c = speed of light = 3* 10^{8}m/s$

Formula that connects wavelength and frequency is:
$frequency= \frac{speed of light}{wavelength} \\ f= \frac{3* 10^{8}}{0.03} \\ f=1 * 10^{10} Hz = 10GHz$

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Two forces are going in opposite directions each force is 9.

professor190 [17]

Answer:

The net force is zero.

Explanation:

Two opposing and equal forces cancel each other out, giving you a net force of zero.

7 0

3 years ago

An object with a mass M = 250 g is at rest on a plane that makes an angle θ = 30 o above the horizontal. The coefficient of kine

liubo4ka [24]

Answer:

v = 79.2 m/s

Solution:

As per the question:

Mass of the object, m = 250 g = 0.250 kg

Angle, $\theta = 30^{\circ}$

Coefficient of kinetic friction, $\mu_{k} = 0.100$

Mass attached to the string, m = 0.200 kg

Distance, d = 30 cm = 0.03 m

Now,

The tension in the string is given by:

$Mgsin\theta + \mu_{k}Mgcos\theta + Ma = T$ (1)

Also

T = m(g + a)

Thus eqn (1) can be written as:

$Mgsin\theta + \mu_{k}Mgcos\theta + Ma = m(g - a)$

$Mgsin\theta + \mu_{k}Mgcos\theta + Ma = mg + ma$

$mg - Mgsin\theta - \mu_{k}Mgcos\theta = (M - m)a$

$a = \frac{0.2\times 9.8 - 0.250\times 9.8\times sin30^{\circ} - 0.1\times 0.250\times 9.8\times cos30^{\circ}}{0.250 - 0.200}$

$a = 10.45\ m/s^{2}$

Now, the speed is given by the third eqn of motion with initial velocity being zero:

$v^{2} = u^{2} + 2ad$

where

u = initial velocity = 0

Thus

$v = \sqrt{2ad}$

$v = \sqrt{2\times 10.45\times 0.03} = 0.792\ m/s$

3 0

3 years ago

The largest building in the world by volume is the boeing 747 plant in Everett, Washington. It measures approximately 632 m long

Schach [20]

Explanation:

Given that,

The dimensions of the largest building in the world is 632 m long, 710 yards wide, and 112 ft high. It basically forms a cuboid. The volume of a cuboidal shape is given by :

Since,

1 meter = 3.28084 feet

632 m = 2073.49 feet

1 yard= 3 feet

710 yards = 2130 feet

V = lbh

$V=2073.49 \ ft\times 2130\ ft\times 112\ ft$

$V=494651774.4\ ft^3$

$V=4.94\times 10^8\ ft^3$

Also,

$V=(4.94\times 10^8\ ft^3)(\dfrac{1\ m}{3.281})^3$

$V=1.39\times 10^7\ m^3$

Hence, this is the required solution.

3 0

3 years ago

In trampoline competitions, a good jump is one that lasts about 1.8 seconds. (A) How high can an athlete who stays in the air 1.

KonstantinChe [14]

Answer:

3.97305 m

Explanation:

a = Acceleration due to gravity = 9.81 m/s²

If a jump lasts for 1.8 seconds this means that from the moment when the person leaves the ground till the person touches the ground again it takes 1.8 seconds. So, maximum height reached will be at half the time of the jump i.e., 0.9 seconds.

u = Initial velocity = 0

Equation of motion

$s=ut+\frac{1}{2}at^2\\\Rightarrow s=0t+\frac{1}{2}9.81\times 0.9^2\\\Rightarrow s=3.97305\ m$

So, height of the jump is 3.97305 m.

4 0

3 years ago

Complete this equation that represents the process of nuclear fusion.

Mars2501 [29]

You need to have the exact amount of atomic number and mass number on each side of the arrow. on the left of the equation Ra has 226 mass and 88 atomic. on the right the He with the atomic number of 2 and the mass number of 4. you’d minus the atomic number on the left with the atomic number on the right (88-2) getting 86 and minus the mass number on the left with the mass number on the right (226-2) which is 224

this means that A = 224 and B = 86

8 0

3 years ago