What is electric charge actually

Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two-types of electric charge; positive and negative. Like charges repel and unlike attract. An object with an absence of net charge is referred to as neutral.

Explanation:

1 the 4 is sig

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.