Which force is sometimes attractive and has an infinite range?
a) strong nuclear
b) weak nuclear
c) gravitational
d) electromagnetic

D) electromagnetic

Explanation:

First of all, we can exclude the following two options:

A) strong nuclear

B) weak nuclear

In fact, these two forces do not have an infinite range, so they cannot be the right option.

We have now two options: gravitational force and electromagnetic force. However, we notice that:

- Gravitational force is always attractive: it acts between every object with mass, and it is always attractive

- Electromagnetic force is sometimes attractive, sometimes repulsive. In particular, it is attractive when we have two charges of opposite sign, and it is repulsive when we have two charges of same sign.

Therefore, since the text of the question says "it is sometimes attractive", the correct option is

D) electromagnetic

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.