## SPEED, VELOCITY AND ACCELERATION

Velocity

Rectilinear Acceleration

Equation of uniformly accelerated motion

Problem solving using equation of motion

Instantaneous Velocity and instantaneous acceleration

Graphical solutions to problems in rectilinear Acceleration

Motion under gravity: Gravitational Acceleration

## What is SPEED in physics

Imagine you’re on your way to school and someone ask you what is SPEED, what will you say?

In a lame man language speed is the number of distance you covered per time taken to cover the distance

IN PHYSICS; SPEED is defined as the rate of change of distance per time

Average speed = distance / time = change in distance / change in time = s/t

D2 – D1/ t2 – t1 = final distance – initial distance/ final time – initial time = s/t

The S.I unit for speed is m/s

### Example 1

A student cover a distance of 5km in 30 minutes. Calculate the average speed?

Average speed = distance/time = 5 Ã— 1000/ 30 Ã— 60

4.17m/s ( 4.17 meter per seconds)

### Example 2

A driver traveling at a speed of 245km/hr received a text message on his mobile phone. How far is he, in kilometers, 30s later from when he received the text?

Speed = 245km/hr, time,t = 20s, ( 30s = 30/3600hr). Distance, s = ?

Distance = speed Ã— time = 245km/hr Ã— 30hr/3600 ( hr will cancel out)

245/120 = 2.04km

## What is velocity?

Velocity is the same thing as speed only that it moves in a specific directions, it is a vector quantity. Velocity can be defined as the rate of change of distance moved with time in a specific direction. It is also defined as the rate of change of displacement with time. Displacement means distance traveled in a specific direction.

Velocity = displacement/time = change in displacement/change in time

=( Final displacement – initial displacement) / (final time – initial time)

However speed is used in place of velocity and vice versa. The S.I unit for velocity is m/s.

To see more related post visit https://www.toppr.com/guides/quantitative-aptitude/averages/average-speed/