*These are some notes from our 9th Std Online Zoom Class – Motion and Equations of motion*

## A brief revision of what we have studied in this class:

EXAMPLE: When velocity keeps **changing continuously**

## Derivations of 3 equations

## PROBLEMS:

**Uniform Acceleration under Gravity**

Bodies dropped from height fall faster and faster. Hence it is accelerated motion.

Gravity is downwards. And hence taken ‘-’

Gravitational acceleration g = 9.8 m/s^{2}

But we consider g = -10 m/s^{2} (for ease of calculation)

Objects dropped from the same height. Who will reach the ground first? (Remember the Videos we saw)

•Elephant and ant

•Small stone and big stone

•Washing machine and a pillow

•Foot ball and iron ball

•A car and a tyre

•Iron ball and a feather

## Projectile Motion

**The Monkey and the banana problem**