Answer:
The poles of an electromagnet can even be reversed by reversing the flow of electricity. If a wire carrying an electric current is formed into a series of loops, the magnetic field can be concentrated within the loops. ... All of their little magnetic fields add together, creating a stronger magnetic field.
Explanation:
Work formula:
W = F * d
F 1 = 40 N, d 1 = 6 m;
F 2 = 30 N; d 2 = 6 m.
W ( Cindy ) = 40 * 6 = 240 Nm
W ( Andy ) = 30 * 6 = 180 Nm
The difference of their amounts if work:
240 Nm - 180 Nm = 60 nm
hope it helps!
Answer:
Explanation:The rotational inertia of any object depends directly on the distance the mass is from the axis of a rotating object
Having more mass at the sides will increase the rotational inertia of the object that is why a Hollow sphere having same M and R as the solid one has more rotational inertia as it has more mass at the sides.
The sphere have some mass at the center but most of its mass is closer to its radius and thus have more inertia than flat Disk.
The same relation exist between a flat disk and hollow sphere. The hollow sphere have some mass at the center but most of its mass is closer to its radius and thus have more inertia.
The rotational of the objects can be calculated by these equations

Answer:
The half-life of a radioactive isotope is the time such that the initial amount of the isotope is reduced to its half.
Thus, if we start with A grams of a given radioactive isotope, after a 1 half-life, we will have A/2 grams of the radioactive isotope.
In this case, we know that the sample has 110g of a radioactive isotope.
Then, after 1 half-life, we should have half of 110g, which is:
110g/2 = 55g
Then we should have 55 g of a radioactive isotope.
The answer that is closer to this result is option d (50 g), so that is the correct one.