Answer:
Doppler shift of the starlight
Explanation:
To predict the movement of a star, we compare the spectra of elements found in star (H, He Na etc.), first spectra which are obtained from star and second spectra from laboratory. If spectral lines of the spectra obtained from star, are shifting towards red end (called red shift) then star is going away from earth and if shifting is towards blue (called blue shift), then star is approaching the earth. This is Doppler's shift.
The correct answer to the question is : Transverse wave.
EXPLANATION :
Before going to answer this question, first we have to understand the longitudinal and transverse wave.
LONGITUDINAL WAVE : A longitudinal wave is a mechanical wave in which the direction of vibration of particles is parallel to the direction of wave propagation. It moves in the form of compression and rarefaction.
For instance, sound wave.
TRANSVERSE WAVE : A transverse wave is a mechanical wave in which the direction of vibration of particles is perpendicular to the direction of wave propagation. It moves in the form of crests and troughs.
For instance, the wave created in a pond when a stone is dropped into it.
Hence, the correct answer of this question is transverse wave.
The last one is correct (D)
Answer:
1050 kg
Explanation:
The formula for kinetic energy is:
KE (kinetic energy) = 1/2 × m × v² where <em>m</em> is the <em>mass in kg </em>and <em>v</em> is the velocity or <em>speed</em> of the object <em>in m/s</em>.
We can now substitute the values we know into this equation.
KE = 472 500 J and v = 30 m/s:
472 500 = 1/2 × m × 30²
Next, we can rearrange the equation to make m the subject and solve for m:
m = 472 500 ÷ (1/2 × 30²)
m = 472 500 ÷ 450
m = 1050 kg
Hope this helps!
