Which group of items all contain a transparent part with at least one curved surface to refract light?

An opera singer in a convertible sings a note at 600 Hz while cruising down the highway at 90km/hr. What is the frequency heard

Inessa05 [86]

Answer:

$f=647.17Hz$

Explanation:

Given data

Frequency fs=600 Hz

Velocity Vs=90 km/hr =25 m/s

Speed of sound v=343 m/s

To find

Frequency f heard by a person standing beside the road in front of the car

Solution

From Doppler's effect we know that:

$f=f_{s}(\frac{v+vL}{v+vs} )\\ as\\vL=0$

Here Vs is negative as the source is moving towards listener

$f=fs(\frac{v+0}{v-vs} )\\f=(600Hz)(\frac{343m/s+0}{343m/s-25m/s} )\\f=647.17Hz$

5 0

4 years ago

The distance between two adjacent peaks on a wave is called the wavelength. The wavelength of a beam of ultraviolet light is 113

Vesna [10]

Answer:

0.000000113 or 1.13* $10^{-7}$ meters

Explanation:

One nanometer is $10^{-9}$ meters. So 113 nanometers would be 113* $10^{-9}$ , or 1.13* $10^{-7}$ meters. That's expessed on "cientific notation." On the "usual" notation, it will be 0.000000113 meters.

3 0

3 years ago

4. What is the magnitude and direction of the gravitational force that acts on a man

Cloud [144]

The gravitational force acting on the man is 800 N towards the Earth's centre

Explanation:

The weight of an object on the Earth is exactly the gravitational force exerted by the Earth on the object.

The gravitational force exerted by the Earth on an object located at the Earth's surface is given by:

$F=G\frac{Mm}{R^2}$

where

G is the gravitational constant

M is the Earth's mass

m is the mass of the object

R is the radius of the Earth

And the direction of the force is towards the Earth's centre.

Since G, M and R are constant, they are grouped into a single constant called g, acceleration of gravity:

$g=\frac{GM}{R^2}$

therefore the gravitational force can be rewritten as

$F=mg$

And this is the usual equation that we use to calculate the weight of an object.

Therefore, weight and gravitational force acting on an object on Earth are the same thing: so, the gravitational force acting on the man is equal to his weight, 800 N, and it acts towards the Earth's center.

Learn more about weight and gravitational force:

brainly.com/question/1724648

brainly.com/question/12785992

#LearnwithBrainly

4 0

3 years ago

What is the difference between mass and weight?

yuradex [85]

The answer is definitely A

8 0

3 years ago

Statement I: At the same temperature lighter gas molecules have a higher average velocity than heavier gas molecules.

PilotLPTM [1.2K]

Answer:

Statement 1 and statement 2 are correct and statement 2 is the correct explanation of statement 1

Explanation:

Both the velocity and kinetic energy of a gas molecule depends on its relative molecular mass according to Graham's law of diffusion in gases. Hence, the greater the relative molecular mass of the gas, the lesser its average velocity and kinetic energy.

Hence we can see that statement 2 vividly explains the postulation of statement 1 and makes the points more easily comprehensible.

6 0

4 years ago