The diagram shows two charged objects, x and y.

based on the field lines, what are the charges of the objects?

a: x: positive
y: negative
b: x: negative
y: positive
c: x: negative
y: negative
d: x: positive
y: positive

D:

X: positive

Y: positive

Explanation:

To answer correctly the question, we need to remind the difference between the electric field produced by a positive charge and by a negative charge:

- For a positive charge, the direction of the field lines is away from the charge (because they represent the direction in which a positive test charge would move, if placed in this field)

- For a negative charge, the direction of the field lines is toward the charge (because the positive test charge would move toward the negative charge, if placed in this field)

In the figure, we see that both charges have electric field lines that go away from the charges: therefore, according to the previous statements, they both have to be positive charges.

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

truck y has a greater velocity than truck x.