Speed is the time rate of an object moving from one place to another, while velocity is the rate and direction of the object's movement. They are very similar but they don't mean the same thing.
Answer:
0.85 A
Explanation:
the effective current is 0.85 A
Not only astronomers, but all scientists use the technique of rock dating to determine the age of the universe. From the Big Bang Theory, all the celestial bodies were made at the same time. So, the age of the Earth is just the same with the age of the universe. So, they gather rocks deep down in the crust of the Earth and let it undergo radioactive decay. By determining the amount of radioactive material left and half-life, they could compute the age of the Earth.
That is -300 J, because the work = the force times the distance. When the distance is a positive value when it is going down, the distance is a negative value when it is going up. The only thing that change is the minus, the absolute value of the work remains the same
