Science Chapter 2: Motion

changing direction

a change in velocity can be either a change in how fast something is moving or change in the direction of movement.

calculating positive acceleration or negative acceleration

a=(vf-vi)/t

...

acceleration can be positive, negative, or zero depending on whether an object is speeding up.

what is Newton's first law?

an object either is at rest or moves at a constant velocity, unless acted upon by an external force.

rate

any change over time

...

anytime a movinfg object changes direction, its velocity changes and it is acclerating.

Which of the following is not used in calculating accelertion?

average speed

Which of the following do you calculate when you divide the total distance traveled by the total travel time?

average speed s=d/t

Which term best describes the forces on an object with a net force of zero?

balanced forces

How can speed be defined?

distanced/time

Acceleration

equals Change in velocity/time or A=change in velocity/time.

speed

equals distance over time or speed = d/t

...

for an object to have constant velocity, speed and direction must not be changing.

balanced forces

forces on an object that are equal in size and opposite in direction are called balanced forces.

speed on speedometer

gives the instantaneous speed-the speed at one instant in time.

reference point

helps you determine how far something has move.

Distance

how far an object has move.

Which of the following is a proper unit of acceleration?

m/s2power

acceleration

occur all around you as objects speed up,slow down, or change direction.

motion

occurs when an object changes direction.

what is the definition of an unbalanced force?

one that is not opposed by an equal and opposite force operating directly against the force intended to cause a change in the object's state of motion or rest.

force

push or pull that one body exerts on another.

acceleration

rate of change of velocity

changing instantaneous speed

speed is differentat every point in time. If and object is moving with constant speed, the instantaneous speed doesn't change. The speed is the same at every point in time.

calculating speed

speed is related to the distance traveled and the time needed to travel the distance

inertia

tendancy of an object to resist any change in its motion.

speed

the distance an object travels per unit of time.

plotting a distance-time graph

the distance is plotted on the vertical axis and the time on the horizontal axis. EACH SCALE MUST HAVE A SCALE THAT COVERS THE RANGE OF NUMBERS YOU ARE WORKING WITH.

...

the slope of a distance-time graph gives the velocity of the object in motion.

velocity

the speed of and object and the direction of its motion.

average speed

the total distance traveled divided by the total time of travel.

net force

when 2 or more forces act on an object at the same time, the forces combine.

changing Instantaneous speed

when something is speeding up or slowing down.

acceleration

when something speeds up

What is the tendency for an object to resist any change in its motion called?

inertia

How do distance and displacement differ?

Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.

What are 2 ex. of motion in which the instantaneous speed change?

Instantaneous speed vs Average speed

Displacement

The distance and direction of an object's change in position from the starting point.

Relative motion

Not all motion is as obvious. Ex even if you are sitting in a chair reading a book you are moving.

...

Remember that velocity includes the speed and direction of an object. Therefore, a change in velocity can be either a change in how fast something is moving or a change in the direction it is moving.

How are velocity and speed different?

Speed, being a scalar quantity, is the rate at which an object covers distance. On the other hand, velocity is a vector quantity; it is direction-aware. Velocity is the rate at which the position changes.

Using the sun as your reference point

You are moving about 30 km through space every second.