Rotation: Ghoomna
Transcript
Kabhi dekha hai ki ek lattu ya fidget spinner ghoomta hai? Aaj hum rotation, yaani ghoomna, samjhenge. Rotation ka matlab hai koi cheez ek fixed point ya line ke around ghoomti hai. Yeh laal dot centre hai. Poori cheez isi centre ke around ghoomti hai.
Neela teer ek radius hai. Jab yeh ghoomta hai, toh ek poora chakkar banta hai. Ek poora chakkar matlab three hundred sixty degrees. Aadha chakkar matlab one hundred eighty degrees.
- Poora chakkar = 360 degrees
\color{blue}{1\ chakkar} = 360^\circAb isi idea ko ek unit circle par dekhte hain. Radius zero degrees se shuru hota hai. Ab radius ko ninety degrees tak ghumate hain. Yeh ek chauthai chakkar hai. Ab one hundred eighty degrees. Radius bilkul ulti taraf chala gaya, yaani aadha chakkar.
- 90 degrees = 1/4 chakkar
- 180 degrees = 1/2 chakkar
Aur do sau sattar degrees par teen chauthai chakkar hota hai. Teen sau saath degrees par hum wapas shuruwat par aa jaate hain. Ek poora chakkar complete. Ek example lete hain. Ek chakkar mein 360 degrees hote hain, toh aadhe chakkar ke liye kitna hoga?
- 270 degrees = 3/4 chakkar
360 \div 2Pehle step mein, teen sau saath ko do se divide karte hain.
360 \div 2 = 180Toh aadhe chakkar mein one hundred eighty degrees hote hain. Bilkul sahi, jaisa humne circle par dekha.
\frac{1}{2} \times 360 = 180^\circAb ek chhota chakkar. Ek chauthai chakkar ke liye teen sau saath ko chaar se divide karo.
360 \div 4 = 90^\circYaad rakho, rotation mein hamesha ek centre hota hai. Bina centre ke ghoomna possible nahi. Ek common galti: log sochte hain ki ghoomne se cheez ka size badal jaata hai. Nahi, size same rehta hai. Ab real life dekhte hain. Space mein pulsar ek tez ghoomta hua neutron star hai.
- Rotation = centre + angle
- Ghoomne se size nahi badalta
Pulsar lighthouse ki tarah ghoomta hai, aur uski beam Earth ki taraf aati hai, toh hume pulse dikhta hai. Pulsar bahut regular ghoomta hai, isliye uske pulses ke beech ka time bilkul precise hota hai. Ab ek quiz. Ek poore chakkar ka matlab kitne degrees hota hai?
- Regular rotation = precise pulses
Summary: rotation matlab centre ke around ghoomna, aur ek poora chakkar teen sau saath degrees ka hota hai.
- Rotation: centre ke around ghoomna
Quick quiz
Q1. Ek poore chakkar mein kitne degrees hote hain?
Ek poora chakkar teen sau saath degrees ka hota hai.
