Question

In what way are gravitational and electrical forces similar?

A. Both occur between objects with large masses.
B. Both occur between objects with large charges.
C. Both occur between objects that have opposite poles.
D. Both occur between objects independently whether they are in contact
or not.

Answer 1

D. Both occur between objects independently whether they are in contact or not.

Step-by-step explanation:

- The gravitational force is a force that is exerted between two (or more) objects having mass. This force is always attractive and its magnitude is given by

`F=G(m_1 m_2)/(r^2)`

where G is the gravitational constant, m1 and m2 are the two masses, and r is the distance between the two masses.

- The electrical force is a force that is exerted between two (or more) objects having electrical charge. It can be either attractive or repulsive, depending on the sign of the two charges, and its magnitude is given by

`F=k(q_1 q_2)/(r^2)`

where k is the Coulomb's constant, q1 and q2 are the two charges, and r the distance between the two charges.

Looking at both formulas, we see that the two forces are present even when the two objects are not in contact with each other (in fact, r can assume any value in the formula). They are said to be non-contact forces. Therefore, the correct option is

D. Both occur between objects independently whether they are in contact or not.