Answer:
The Doppler effect is a change in the frequency of sound waves that occurs when the source of the sound waves is moving relative to a stationary listener. Sound waves that are closer together have a higher frequency, and sound waves that are farther apart have a lower frequency.
Explanation:
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Explanation:
It is given that,
Mass of platinum bar, m = 750 g
Length of the bar, l = 5 cm
Breadth of the bar, b = 4 cm
Width of the bar, h = 1.5 cm
Volume of the bar, 

We need to find the density of the platinum bar. The density of any substance is given by :



So, the density of the platinum bar
. Hence, this is the required solution.
Answer:
7.77 x 10⁸ Km
Explanation:
given,
Speed of light = 3 x 10⁵ Km/s
= 3 x 10⁸ m/s
1 light hour = 1.079 x 10⁹ Km
now,
0.72 light hour = 0.72 x 1.079 x 10⁹ Km
= 0.7769 x 10⁹ Km
= 7.77 x 10⁸ Km
The Jupiter is 7.77 x 10⁸ Km far from sun.
Balance means net force equals zero