# How do we describe motion?

In physics,

**motion**is a change in position of an object over time.**Motion**is**described**in terms of displacement, distance, velocity, acceleration, time, and speed. As there is no absolute frame of reference, absolute**motion**cannot be determined. Thus, everything in the universe can be considered to be moving.A.

### What is the position of an object?

You can describe the motion of an

**object**by its**position**, speed, direction, and acceleration. Page 2. 4 Linear Motion. An**object**is moving if its**position**relative to a fixed point is changing. 4.1 Motion Is Relative.#### How can you tell if an object is in motion?

An**object is in motion**if its distance relative to another**object**is changing.**To tell**if an**object**is moving, you use a reference point. If an**object's**distance from another**object**[reference point] is changing. A place or**object**used for comparison to determine if something is in**motion**.#### What is the unit for speed and velocity?

The SI unit of time is the**second**. The SI unit of speed and velocity is the ratio of two — the**meter**per**second**. This unit is only rarely used outside scientific and academic circles. Most people on this planet measure speeds in kilometer per hour (km/h or sometimes kph).#### What is the velocity of an object?

For example, "5 metres per second" is a scalar, whereas "5 metres per second east" is a vector. If there is a change in speed, direction or both, then the**object**has a changing**velocity**and is said to be undergoing an acceleration.

B.

### How is position related to motion?

An object is in

**motion**when its**position**is changing. Speed describes how far an object moves in a given amount of time (for example, miles per hour). A force is a push or pull that can cause an object to move, stop, or change speed or direction.#### What is the formula for calculating speed?

The speed of an object is how fast or**slow**it's moving. You can calculate speed using the equation 'speed =**distance**/time'.**Distance**-time graphs illustrate how an object moves. They show how the**distance**moved from a starting point changes over time.#### What do you call the change in position?

Speed in a specific direction is**called**velocity. 17. Acceleration measures**change**in speed or direction. 18. A**change in position**over time is**called**speed.#### What is the change in position of an object per unit of time?

The unit of acceleration is change of position per unit of time per unit of time, such as meters/**second**/**second**. Acceleration can be positive or negative. Velocity is an object's change of position per unit of time. Acceleration is the rate at which velocity changes in a unit of time.

C.

### How do you describe the position of an object?

You can

**describe**the motion of an**object**by its**position**, speed, direction, and acceleration. An**object**is moving if its**position**relative to a fixed point is changing. Even things that appear to be at rest move.#### What is meant by a body at rest?

**Rest**is a state in physics that refers to an object being stationary relative to a particular frame of reference or another object; when the position of a**body**with respect to its surroundings does not change with time it is said to be "at**rest**".#### How do you measure the speed of a moving object?

The**speed of an object**is how fast or slow it's moving.**You**can**calculate speed**using the**equation**'**speed**= distance/time'. Distance-time graphs illustrate how an**object**moves. They show how the distance moved from a starting point changes over time.#### What is the unit for speed and velocity?

The SI unit of time is the**second**. The SI unit of speed and velocity is the ratio of two — the**meter**per**second**. This unit is only rarely used outside scientific and academic circles. Most people on this planet measure speeds in kilometer per hour (km/h or sometimes kph).

Updated: 2nd October 2019