Answer: Earth's magnetic field has flipped its polarity many times over the ... Earth has settled in the last 20 million years into a pattern of a pole reversal about ... And while reversals have happened more frequently in "recent" years, when ... per year, as opposed to about 10 miles per year in the early 20th century.
Explanation:
The answer is A because t<span>he speed of light is constant in vacuum and unaffected by the speed of the source emitting the light</span>
Answer:
now his maximum speed is given as
Explanation:
Total time for which Usain Bolt accelerated is given as
now the velocity after uniform acceleration is given as
now remaining time for which he run for the finish line is given as
now the distance moved by him during uniform acceleration is given as
another distance that he moved for uniform speed is given as
now total distance moved by him is 100 m so we have
now his maximum speed is given as
Answer:
66.475kJ
Explanation:
Work done is the product of the force and perpendicular distance in direction of the force.
Work done = Force × distance
Given
Weight = 700lb
Distance = 70ft
1lb force = 4.448N
700lb force = 700(4.448) = 3113.6N
Distance = 70(0.305) = 21.35m
Work done = 3113.6×21.35
Work done ≈ 66,475Joules
Work done = 66.475kJ
The planetary wind belts in the troposphere are primarily caused by the Earth's rotation and the unequal heating of Earth's surface.
Planetary wind belts are vast movements and they are driven by the circulation of air. The Sun's heat causes the winds around the world. It heats the tropical zone primarily than the polar regions because the sun's rays are more direct at the equator.