Motion

What Do We Mean By Speed? Exactly how fast are you running? How many meters do you run for each second? Do you always run the same number of meters each second?

Speed The speed of an object is a measure of how quickly the object gets from one place to another. Speed is calculated by taking the distance traveled by the time taken. Speed = distance/time V = d/t

Forms of the Speed Equation Gives you… If you know… v = d/t Speed time and distance d = vt Distance speed and time t = d/v time distance and speed

Velocity Velocity is the quantity describing both speed and direction. Velocity = distance/time in a specific direction Velocity can change without the speed changing.

Acceleration Acceleration is the rate of change in velocity. If either speed or direction changes, the velocity will change. Acceleration can occur through a change in speed or change in direction.

Acceleration (2) Acceleration can be positive or negative. When a car comes to a stop, this is called deceleration. The speed is increasing, so the acceleration is positive. The speed is decreasing, so the acceleration is negative.

Acceleration Formula a = v2 – v1/time v2 is the final velocity v1 is the beginning or initial velocity.

What Does an Acceleration Value Tell You? If the acceleration is small, that means the speed is increasing very gradually. If the acceleration has a greater value, the object is speeding up more rapidly. If an object has zero acceleration, then it is traveling at a constant speed in one direction.