Question

14 how could you double the acceleration of an object in motion? 15 the resistance of an object to any change in its motion is called... 16 the force that opposes motion between two surfaces in contact with each other.

Explanation:

Step1: Recall Newton's second - law

Newton's second - law is $F = ma$, where $F$ is force, $m$ is mass and $a$ is acceleration. We can express acceleration as $a=\frac{F}{m}$.

Step2: Analyze how to double acceleration

If we want to double the acceleration $a$, from $a=\frac{F}{m}$, we can either double the force $F$ (while keeping $m$ constant) or halve the mass $m$ (while keeping $F$ constant). Among the given options, doubling the force is correct for the first question.
The resistance of an object to any change in its motion is called inertia.
The force that opposes motion between two surfaces in contact with each other is called friction.

Answer:

1. double the force
2. inertia
3. friction