Answer:
Radio waves and gamma rays have a common speed when they propagate in a vacuum. This speed is:
Explanation:
Gamma rays are produced naturally by atomic nuclei during their natural radiative transformations, and their wavelength is less than .
Such radiation has the property of ionizing atoms and also has great penetrating power. For its absorption, it is very common to use thick lead walls.
Radio waves are those with the lowest frequency and, consequently, the longest wavelengths, ranging from 10 m to 10 km. They are widely used in radio and TV broadcasts. These waves were generated for the first time by the German physicist Heinrich Rudolf Hertz, whose experiment was perfected, eight years later, by the Italian Guglielmo Marconi.
The speed of radio waves and river ranges in a vacuum is the same, this is something they have in common, their approximate value is:
Answer:
The work done by friction was
Explanation:
Given that,
Mass of car = 1000 kg
Initial speed of car =108 km/h =30 m/s
When the car is stop by brakes.
Then, final speed of car will be zero.
We need to calculate the work done by friction
Using formula of work done
Put the value of m and v
Hence, The work done by friction was
Answer:
Explanation:
For this case we can use the second law of Newton given by:
The friction force on this case is defined as :
Where N represent the normal force, the kinetic friction coeffient and a the acceleration.
For this case we can assume that the only force is the friction force and we have:
Replacing the friction force we got:
We can cancel the mass and we have:
And now we can use the following kinematic formula in order to find the distance travelled:
Assuming the final velocity is 0 we can find the distance like this: