All categories

4 years ago

How are light and sound waves affected by the different media they travel though?

1 answer:

8 0

Sound waves need to travel through a medium such as solids, liquids and gases. The sound waves move through each of these mediums by vibrating the molecules in the matter. The molecules in solids are packed very tightly. Liquids are not packed as tightly. And gases are very loosely packed. This enables sound to travel much faster through a solid than a gas. Sound travels about four times faster and farther in water than it does in air.

Light waves do not require a medium to travel. This is how light can travel through space and we can see stars. Light waves travel at a much higher velocity as compared to sound waves. The velocity of light waves (through a vacuum) is 3 xx 10^8 m/s. In comparison, the velocity of sound waves (in air) is about 343 m/s. Different frequencies of light waves give rise to different colors. On the other hand, different frequencies of sound waves result in different pitches. Light waves and sound waves have very different frequencies from each other. Sound waves have low frequencies (20 to 20,000 Hz) as compared to light waves (~ 10^14 Hz).

You might be interested in

8. An unpowered flywheel is slowed by a constant frictional torque. At time t = 0 it has an angular velocity of 200 rad/s. Ten s

allsm [11]

Answer:

a) $\omega = 50\,\frac{rad}{s}$ , b) $\omega = 0\,\frac{rad}{s}$

Explanation:

The magnitude of torque is a form of moment, that is, a product of force and lever arm (distance), and force is the product of mass and acceleration for rotating systems with constant mass. That is:

$\tau = F \cdot r$

$\tau = m\cdot a \cdot r$

$\tau = m \cdot \alpha \cdot r^{2}$

Where $\alpha$ is the angular acceleration, which is constant as torque is constant. Angular deceleration experimented by the unpowered flywheel is:

$\alpha = \frac{170\,\frac{rad}{s} - 200\,\frac{rad}{s} }{10\,s}$

$\alpha = -3\,\frac{rad}{s^{2}}$

Now, angular velocities of the unpowered flywheel at 50 seconds and 100 seconds are, respectively:

a) t = 50 s.

$\omega = 200\,\frac{rad}{s} - \left(3\,\frac{rad}{s^{2}} \right) \cdot (50\,s)$

$\omega = 50\,\frac{rad}{s}$

b) t = 100 s.

Given that friction is of reactive nature. Frictional torque works on the unpowered flywheel until angular velocity is reduced to zero, whose instant is:

$t = \frac{0\,\frac{rad}{s}-200\,\frac{rad}{s} }{\left(-3\,\frac{rad}{s^{2}} \right)}$

$t = 66.667\,s$

Since $t > 66.667\,s$ , then the angular velocity is equal to zero. Therefore:

$\omega = 0\,\frac{rad}{s}$

7 0

3 years ago

What does the equation n =Pout/Pin mean

V125BC [204]

Basically, the variable n is equal to the amount of P out of the system divided by the about of P into the system

7 0

3 years ago

Read 2 more answers

If I travel 300 m east, then 400 m west, what is my distance & displacement?

ad-work [718]

Answer:100m west

Explanation:

6 0

3 years ago

You are a crane operator using a wrecking ball to demolish an old building. You can choose to use a 100-kg ball or a 150-kg ball

Elenna [48]

Answer:

The answer to the question is

The two balls, although of different masses, could be made to have the same demolishing force by setting the velocity of the 100 kg ball to 1.5 times the velocity of the 150 kg ball.

That is if V₁ is the velocity of the 150 kg ball and V₂ is the velocity of the 100 kg ball then V₂ = 1.5×V₁ for the demolishing effect of the two balls to be equal.

Explanation:

To answer the we are required to explain the meaning of momentum and state its properties

Momentum is a physical property of an object in motion. It indicates the amount of motion inherent in the object. An object in motion is said to have momentum

The types of momentum possessed by an object can be classified into either

1, Linear momentum or

2. Angular momentum

An object moving with a velocity, v has linear momentum while a spinning object has an angular momentum

The momentum is given by the formula

P = m × V

Where m = mass and

V = velocity

Newtons second law of motion states that, the force acting on an object is equivalent to the rate of change of momentum produced and acting in the direction of the force

Properties of momentum

From the above statements it means that the two balls can be made equivalent by having the appropriate amount of speed. That iis the two balls can have the same momentum thus for equal momentum effect, we have

150 kg × V₁ = 100 kg × V₂

or V₂ = 1.5×V₁

3 0

4 years ago

A train starts at rest in a station and accelerates at a constant 0.987 m/s2 for 182 seconds. Then the train decelerates at a co

algol [13]

Answer:

$\displaystyle X_T=66.6\ km$

Explanation:

Accelerated Motion

When a body changes its speed at a constant rate, i.e. same changes take same times, then it has a constant acceleration. The acceleration can be positive or negative. In the first case, the speed increases, and in the second time, the speed lowers until it eventually stops. The equation for the speed vf at any time t is given by

$\displaystyle V_f=V_o+a\ t$

where a is the acceleration, and vo is the initial speed .

The train has two different types of motion. It first starts from rest and has a constant acceleration of $0.987 m/s^2$ for 182 seconds. Then it brakes with a constant acceleration of $-0.321 m/s^2$ until it comes to a stop. We need to find the total distance traveled.