Many a student find Free Fall Equations tough, but the students at STEPS (A program run by TCYin Ludhiana, Ambala, Jammu, Karnal and Kurukshetra for NTSE and NSEJS aspirants) just solve the toughest of Free Fall problems mentally. I would like to share their secret with you.
The first basic principle is the time taken for a change in Velocity under uniform acceleration is given by, “change in velocity/acceleration”
The second principle is that when you throw a ball up with a velocity of say 20 m/s, then it returns back with a velocity -20 m/s. So the change in velocity is 40 m/s in the direction of acceleration. To simplify things the change in velocity is simply double the initial velocity.
Using these two principles let us try to calculate time of flight of a ball thrown up with a speed of 25 m/s.
Change in velocity =50 m/s
Acceleration = 10 m/s2
Time = 5 s
Now isn’t that easy!
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