Answer:
d: +3
Explanation:
X1 is going +3 meters to arrive to X2. More scientifically -6+3= -3 which is the value of X2 which tells us that the correct answer is +3.
Answer:
about 200k years
Explanation:
because we were migrating as cavemans.
The heavier the object the faster it will fall. The lighter the object the slower to fall. You can test this for example with a rock and a piece of paper. The paper will take more time to for it to hit the ground rather than the rock which will be quicker.
Answer:
The frequency of the radio wave is 
Explanation:
The electromagnetic spectrum is the distribution of radiation due to the different frequencies at which it radiates and its different intensities, that radiation is formed by electromagnetic waves, which are transverse waves formed by an electric field and a magnetic field perpendicular to it.
Radiation is distributed along that electromagnetic spectrum according with the wavelength or frequency. For example, X-rays, ultraviolet rays, the visible region are the ones with the highest frequencies and infrared, microwave and radio waves with lower frequencies.
Light propagates as electromagnetic wave in vacuum with a speed of
. Therefore, radio waves will have in vacuum the same speed.
Therefore, in order to know the frequency the following equation can be used:
(1)
(2)
Where
is the frequency, c is the speed of light and
is the wavelength.
Hence, the frequency of the radio wave is
.