Physical changes are those change which just externally or physically change the state of the object . for example : water boils and evaporates... here the state is just changing from liquid to vapour while the composition is the same.
chemical changes are those which bring about a change in the composition of a substance. for example: burning of paper changes into ash .
Velocity =displacement
Change in time
D=72km/hr
Time=20s
But the S.I unit of velocity is m/s so you woul have to change 72km/hr to m/s
Changing 72km to m
1 kilometer=1000meters
Then, 72 kilometers =?
72•1000/1
=72000m
Changing 72hours to seconds
If 1 hour = 3600 seconds
Then 72 hours=?
72•3600/1
=259200 seconds
Velocity =displacement
Change in time
V= 72,000
259,2005
=0.028m/s
This would happen later at night or early in the morning.
The reason being land becomes warm and cold quicker than the water because of the heat capacity. So during the day water warms up because of sunlight but at night the land becomes a lot cooler as compared to the water which is still war. So the air over water is significantly warmer than the air over land.
Answer:
Make sure everything is organized have a planner it can help
Get rid of all distractions
Listen to music if it helps you concentrate
Have your notes
Being willing to stay focus on what you are doing
Understand what you are doing
And most off all Be Happy and Remain Calm : )
