### A passenger in the rear seat of a car moving at a steady speed us at rest relative to?

The front seat of the car

### A person walks 1 mile every day for exercise, leaving her front porch at 9:00 am. and returning to her front porch at 9:25 am. What is the total displacement of her daily walk?

0

### A person drives north 6 blocks, then turns west, and drives 6 blocks. The driver then turns south and drives 6 blocks. How could the driver have made the distance shorter while maintaining the same displacement?

By driving west 6 blocks from the starting point

### A ball is rolled uphill a distance of 5 meters before it slows, stops and begins to roll back. The ball rolls downhill 9 meters before coming to rest against a tree. What is the magnitude of the ball's displacement?

4 meters

### Displacement vectors of 4 km south, 2 km north, 5 km south, and 5 km north combine to a total displacement of?

2 km south

### Speed is the ratio of the distance an object moves to

the amount of the time needed to travel the distance

### What identifies a change in motion that produces acceleration?

a ball moving at a constant speed around a circular track

### What's an example the describes constant acceleration due ONLY to a change in direction?

traveling around a circular track

### The direction and length of a straight line from the starting point to the ending point of an object's motion is?

Displacement

### Displacement and velocity are examples of what? because they have both magnitude and direction.

vectors

### The difference between speed and velocity indicates the _____ of motion and speed does not

direction

### The velocity of an object moving in a straight line changes at a constant rate when the object is experiencing constant _____

acceleration

### The acceleration of a moving object is calculated by dividing the change in _____ by the time over which the change occurs.

speed

### Mass:

Is the amount of matter in an object, a measure of the inertia of an object, which depends on the amount of matter the object contains

### Inertia:

An object that is in motion stays in motion and an object at rest stays at rest as long as the net forces acting on that object are zero

### What is a net force?

forces combined when they are acting on an object (they can be pushed or pulled)

### What do we call it when net forces are zero acting on an object (so there is no change in the object's motion)?

balanced force

### Newton's Third Law of Motion

For every action there is an equal and opposite reaction.

Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object.

### (True or False) Only when equal and opposite forces act on the same object do they result in a net force of zero.

True