When a force is applied to an object for an amount of time, it is known as

a. momentum
b. acceleration
c. inertia
d. impulse

The correct answer to the question is : D) Impulse

EXPLANATION:

Before going to answer this question, first we have to understand impulse.

Impulse of a body is defined as change in momentum or the product of force with time.

Mathematically impulse = F × t = m ( v - u ).

Here, v is the final velocity

          u is the initial velocity

          F is the force acting on the body for time t.

Hence, the perfect answer of this question is impulse m i.e the force multiplied with time is known as impulse.

d) the number of neutrons plus the number of protons