Answer: B. A gravitational field
Explanation:
Surrounding earth is gravitational field. Gravitational field is a region of space were gravitational force can be felt and gravitational force is the gravitational pull on the surface of the earth. The presence of this gravity is what allow us to be able to walk freely without falling. It also make us jump up and be able to land back on the ground. Assuming there are no force of gravity in the surface of the earth, there won't be any possibility of landing back on the ground after jumping.
Answer:
1.24
Explanation:
The resistivity of copper
The resistivity of Aluminum,
The wires have same resistance per unit length.
The resistance of a wire is given by :

According to given condition,

So, the required ratio of the diameter of Aluminum to Copper wire is 1.24.
When storm clouds produce lightening and thunder, then, potential energy changes into kinectic energy.
The clouds become negatively charged,and the ground is positively charged during a storm. So there creates a potential difference between the charged clouds and the ground. And when this becomes huge so much that it over comes the electrical insulation cover of air, the electrons jump to the ground.i.e. the potential energy changes into kinetic energy.
Weathering and rock slides
The eastern time zone would the opposite side of the angle made by his car. So this means he would be traveling 30cos30 m/s completely in the east direction. Or approximately 26 m/s in the East direction. 5000 m divided by this answer results in approximately 192 seconds. I would use a calculator to get a more exact answer