Answer: Mechanical waves carry energy through a medium; electromagnetic waves carry energy through media and space.
Explanation:
<u>The waves which require medium to travel are known as mechanical waves. </u>The waves carry energy forward by compression and rarefaction that is by changing density /pressure of medium particles.
<u>Electromagnetic waves can transfer energy through space as well as medium. </u>In an electromagnetic wave, electric field generates magnetic field and magnetic field generates electric field. Electric field and magnetic field are perpendicular to each other and to the direction of motion.
Answer:
d) The speed of the astronaut
Explanation:
The sentence describes the speed of the astronaut. This speed value is 10meters per minute.
Now let us understand why;
- Speed is the distance divided by time. It is a scalar quantity without regard for direction but it has magnitude.
- The value 10meters per minute clearly shows this instance. We do not know the direction the astronaut is moving towards.
- Velocity, like speed is the displacement of a body with time. It is a vector quantity and it shows the direction of motion.
- For example, 10m/s due west is a velocity value because we know the direction.
Therefore, since there is no directional sense, the value indicates speed.
The electrical forces pulls nucleus apart
Answer:
finding Cepheid variable and measuring their periods.
Explanation:
This method is called finding Cepheid variable and measuring their periods.
Cepheid variable is actually a type of star that has a radial pulsation having a varying brightness and diameter. This change in brightness is very well defined having a period and amplitude.
A potent clear link between the luminosity and pulsation period of a Cepheid variable developed Cepheids as an important determinants of cosmic criteria for scaling galactic and extra galactic distances. Henrietta Swan Leavitt revealed this robust feature of conventional Cepheid in 1908 after observing thousands of variable stars in the Magellanic Clouds. This in fact turn, by making comparisons its established luminosity to its measured brightness, allows one to evaluate the distance to the star.
Answer:
B. people with OCD know their disorder is irrational
Explanation:
Got it right
