Answer: unless it's acted upon by an external force
Explanation: Newton first law of motion State that an object will continue in it state of rest or in motion, unless it is been acted upon by an external force
Answer:
7) 
8) 
9) 
10) 
Explanation:
For the problems 7, 8 and 9 we just apply the definition of acceleration, since no more information is given, which is:

So for each problem we will have:
7) 
8) 
9) 
For the problem 10, we use the equation of velocity in accelerated motion:

Since the ball starts from rest and the acceleration is that of gravity (we take the downward direction positive), we have:

1.6e-6 gl on the rest of your physics its a killer for me too