Question

physics unit 3a motion newtons laws overview gpb.org/physics - motion note - taking guide and questions to consider name: date: answer the following. 1. when an object experiences an unbalanced force, how must it be moving? 2. if an object is being pulled by two forces, one 4 n to the left and the other 2 n to the right, what is the net force acting on the object? 3. define newtons first law in your own words. 4. what is the common name for newtons first law? 5. what physical quantity that can be measured relates directly to inertia? 6. if two objects experience the same net force, but they have different masses, which object will accelerate at a greater rate - the lighter or heavier object?

Explanation:

1. According to Newton's second law ($F = ma$), when there is an unbalanced force, the object must be accelerating.
2. Net force is calculated by subtracting the smaller force from the larger one in the case of forces in opposite - directions. So, net force $F_{net}=4N - 2N=2N$ to the left.
3. Newton's first law states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
4. The common name for Newton's first law is the law of inertia.
5. Mass is the physical quantity that relates directly to inertia. A larger mass means more inertia.
6. From Newton's second law $a=\frac{F}{m}$, when $F$ is the same, a lighter object (smaller $m$) will have a greater acceleration.

Answer:

1. It must be accelerating.
2. 2 N to the left
3. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
4. The law of inertia
5. Mass
6. The lighter object