Answer:
<em>The first law states that</em> every planet describes an elliptical path about the sun as a single focus.
<em>The</em><em> </em><em>second</em><em> </em><em>law</em><em> </em><em>states</em><em> </em><em>that</em><em> </em>The line joining the planet to the sun sweeps out equal areas in equal time intervals.
<em>The</em><em> </em><em>third</em><em> </em><em>law</em><em> </em><em>states</em><em> </em><em>that</em><em> </em>The squares of the period of revolution is proportional to the cubes of the mean distance between the planet and the sun
<h3>Answer:</h3>
The mechanical advantage would decrease, making the block more difficult to lift.
<h3>Explanation:</h3>
The mechanical advantage in such a setup is the ratio of distance from A to B to the distance from D to B. In this picture, that ratio is less than 1, meaning the advantage of having this setup is less than the advantage of no setup at all.
While the force required to lift the block is increased by this setup, the distance over which that force is applied will be smaller for raising the block to a given height. (Overall, for the same height, more work is required with the lever setup because you're raising part of the mass of the lever as well as the mass of the block.)
Answer:
I = 1.875 A
Explanation:
For this exercise we use Ampere's law
∫ B . ds = μ₀ I
We use a circular path around the wire whereby B and ds are parallel, whereby the dot product is reduced to the algebraic product
ds = 2π dr
B (2πr) = μ₀ I
I = B 2π R /μ₀
r= 7.5 cm = 0.075 m
calculate
I = (50 μ₀ /π) 2π 0.075 /μ₀
I = 1.875 A
They would have disliked that they had to relearn how to measure.