In vacuum , the shorter the wavelength of an electromagnetic wave is , the:

The throwing back by a wall or barrier of a sound wave without absorbing<br> it. *<br> 1 point

Semenov [28]

Answer:Reflection

Explanation:

The throwing back of a sound wave without absorbing it is called reflection

In acoustic reflection of sound is termed as echo i.e. sound arrived at the listener after a particular delay depending upon the position of barrier to the observer.

The reflection of sound is used in many devices like megaphone, trumpets, etc. It is also used in auditorium such that the ceiling of the auditorium is curved for multiple reflections of sound so that sound can be reached at every corner of the auditorium.

8 0

2 years ago

A can of beans that has mass M is launched by a spring-powered device from level ground. The can is launched at an angle of α0 a

scZoUnD [109]

Hi there!

A.

Since the can was launched from ground level, we know that its trajectory forms a symmetrical, parabolic shape. In other words, the time taken for the can to reach the top is the same as the time it takes to fall down.

Thus, the time to its highest point:
$T_h = \frac{T}{2}$

Now, we can determine the velocity at which the can was launched at using the following equation:
$v_f = v_i + at$

In this instance, we are going to look at the VERTICAL component of the velocity, since at the top of the trajectory, the vertical velocity = 0 m/s.

Therefore:
$0 = v_y + at\\\\0 = vsin\theta - g\frac{T}{2}$

***vsinθ is the vertical component of the velocity.

Solve for 'v':
$vsin(\alpha_0) = g\frac{T}{2}\\\\v = \frac{gT}{2sin(\alpha_0)}$

Now, recall that:
$W = \Delta KE = \frac{1}{2}m(\Delta v)^2$

Plug in the expression for velocity:
$W = \frac{1}{2}M (\frac{gT}{2sin(\alpha_0)})^2\\\\\boxed{W = \frac{Mg^2T^2}{8sin^2(\alpha _0)}}$

B.

We can use the same process as above, where T' = 2T and Th = T.

$v = \frac{gT}{sin(\alpha _0)} }\\\\W = \frac{1}{2}M(\frac{gT}{sin(\alpha _0)})^2\\\\\boxed{W = \frac{Mg^2T^2}{2sin^2(\alpha _0)}}$

C.

The work done in part B is 4 times greater than the work done in part A.

$\boxed{\frac{W_B}{W_A} = \frac{4}{1} = 4.0}$

4 0

2 years ago

If a single circular loop of wire carries a current of 62 A and produces a magnetic field at its center with a magnitude of 1.20

s2008m [1.1K]

Given Information:

Current in loop = I = 62 A

Magnitude of magnetic field = B = 1.20x10⁻⁴ T

Required Information:

Radius of the circular loop = r = ?

Answer:

Radius of the circular loop = 0.324 m

Explanation:

In a circular loop of wire with radius r and carrying a current I induces a magnetic field B which is given by

B = μ₀I/2r

Please note that for an infinitely straight long wire we use 2πr whereas for circular loop we use 2r

Where μ₀= 4πx10⁻⁷ is the permeability of free space

Re-arranging the equation yields

r = μ₀I/2B

r = 4πx10⁻⁷*62/2*1.20x10⁻⁴

r = 0.324 m

Therefore, the radius of this circular loop is 0.324 m

3 0

3 years ago

HURRY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Paha777 [63]

Light sound and thermal

6 0

2 years ago

Read 2 more answers

At 10:17 a.m., you pass a police car at 55 mph that is stopped on the freeway. You pass a second police car at 55 mph at 10:53 a

Stells [14]

Answer:

The police will cite you for speeding.

Explanation:

To know if the police will cite you for speeding we need to find the average speed (v):

$v = \frac{x_{f} - x_{i}}{t_{f} - t_{i}}$

<u>Where:</u>

x(f): is the final distance = 39 mi

x(i): is the initial distance = 0

t(f): is the final time = 53 min = 0.88 h

t(i): is the initial time = 17 min = 0.28 h

Hence, the average speed is:

$v = \frac{39 mi - 0}{0.88 h - 0.28 h} = 65 mph$

Therefore, since the limit speed is 60 mph and your speed is 65 mph, the police will cite you for speeding.

I hope it helps you!

5 0

2 years ago