(1) acceleration, a = 4 m/
(2) acceleration of 10 N,
= 1 m/
and acceleration of 30 N,
= 3 m/
Explanation:
- Here, the acceleration of the object could be found using the equation derived in the second law of motion. The equation is given as, F = ma where m is the acceleration of the object, m is the mass of the object and F is the applied on the object.
- Let
be the acceleration for force 10 N, to find acceleration rearrange the equation to a =
. When we substitute 10 N force and 10 kg mass of the box in the equation. We will get
= 1 m/
- Let
be the acceleration for force 30 N, to find acceleration rearrange the equation to F =
. When we substitute 30 N force and 10 kg mass of the box in the equation. We will get
= 3 m/
- To find the combined, just add the force and substitute in the above equation. Hence, a = 4 m/

Answer:
a reference point allows you to determine the motion of an object :)
example: when your in a car and u look out the window and your moving fast than the car next to you. It seems that way because the car next to you is actually moving much slower.
If the billiard ball is going at the constant speed and contains its mass then the momentum WONT be changing. But realistically you have external forces like friction and air resistance changing the velocity thus changing the momentum. In this case momentum is not conserved because you're introduction an external force.