Force is an influence that can cause an object to change its velocity, i.e., to accelerate, unless counterbalanced by other forces. The concept of force makes the everyday notion of pushing or pulling mathematically precise.   Forces Acting in Opposite Directions:  When two forces act on an object in opposite directions, the net force is equal to the difference between the two forces. The net force is calculated by subtracting the lesser force from the greater force. How opposing forces affect the motion of an object depends on whether the forces are balanced or unbalanced.     - If... Show more

Force is an influence that can cause an object to change its velocity, i.e., to accelerate, unless counterbalanced by other forces. The concept of force makes the everyday notion of pushing or pulling mathematically precise.
 

Forces Acting in Opposite Directions:  When two forces act on an object in opposite directions, the net force is equal to the difference between the two forces. The net force is calculated by subtracting the lesser force from the greater force. How opposing forces affect the motion of an object depends on whether the forces are balanced or unbalanced.    
- If opposing forces are balanced, they are equal in strength and the net force is zero. With a net force of zero acting on an object, its motion does not change. If it isn't moving, it remains stationary. If it is moving, its speed and direction do not change.    
- If opposing forces are unbalanced, they are not equal in strength and the net force is greater than zero. With a net force greater than zero acting on an object, its motion changes. If it is stationary, it starts moving. If it is already moving, its speed or direction changes.

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Middle School Physical Science: Forces - What is Force?

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7 Questions

1. If gravity pulls you down toward the center of Earth with a force of 500 N, how much upward force does the ground exert on you?

50 Nnone of these500 N0 N

2. In the following sketch, what is the net force acting on the box?

15 N to the left5 N to the left15 N to the right5 N to the right

3. Which pair of forces below produces a net force of zero?

cabd

4. Force can cause a

stationary object to start moving.moving object to change direction.moving object to change speed.all of these

5. Which diagram represents balanced forces?

dcba

6. Which pair of forces below differ from each other in both strength and direction?

abdc

7. Examples of forces include

acceleration.two of thesefriction.motion.