Welcome To My School Study
Do You Know
1. Basic Unit of Time – Second (s)
The second is the standard (SI) unit used to measure time. All other units like minutes, hours, and days are based on seconds.
Understanding it:
- 1 minute = 60 seconds
- 1 hour = 3600 seconds
Why important:
Time measurement helps us understand motion, speed, and duration of events accurately.
Example:
A stopwatch measures time in seconds during a race.
2. Speed (Distance covered in unit time)
Speed tells us how fast an object is moving. It is defined as the distance travelled in a given amount of time.
Formula:
Speed = Distance ÷ Time
Understanding it:
If an object covers more distance in less time, it has higher speed.
Example:
- A car covering 60 km in 1 hour has a speed of 60 km/h
- A person walking slowly has lower speed
3. Speedometer (Measuring Speed of Vehicles)
A speedometer is a device used to measure the instant speed of a moving vehicle.
Where it is found:
It is fitted in vehicles like bikes, cars, and buses.
Difference from odometer:
- Speedometer → shows speed
- Odometer → shows total distance travelled
Example:
When you drive a bike, the needle or digital display shows your speed in km/h.
4. Simple Pendulum – Periodic Motion
A simple pendulum is an example of periodic motion, which means motion that repeats itself at equal intervals of time.
What is a pendulum?
It is a small object (bob) tied to a string and allowed to swing back and forth.
Why periodic:
Its motion repeats again and again in the same pattern.
Example:
- Wall clock pendulum
- Swing in a playground
5. Speed Formula (Distance ÷ Time)
Speed is calculated by dividing the distance travelled by the time taken.
Formula:
Speed = Distance ÷ Time
Understanding it:
- More distance in less time → higher speed
- Less distance in more time → lower speed
Units of speed:
- m/s (meter per second)
- km/h (kilometer per hour)
Example:
If a car travels 100 km in 2 hours,
Speed = 100 ÷ 2 = 50 km/h
