Velocity Problem?

Question

What is the instantaneous velocity of a freely falling object 10 s after it is released from a position of rest?
What is its average velocity during this interval?
How far will it fall during this time?

please provide an explanation to answers

Answer 1

Presuming no air drag, v = u + gt; where v is end velocity after t time elapsed since being let go at initial velocity u and accelerating at g = 9.81 m/sec^2 on Earth's surface. If u = 0, the v = gt ~ 10*10 = 100 m/sec. [NB: I'm using g ~ 10 m/sec^2 for ease of calculation. If you need more precision, use g = 9.81 m/sec^2 instead.]

v avg * t = S; where t = 10 sec and S = distance covered in ten seconds (t). v^2 = 2gS when u = 0; so S = v^2/2g and v avg = v^2/2g//t ~ 10^4/2*10//10 = 1/2*10^2 = 50 m/sec is about the average velocity. S = 10^4/2*10 = 1/2*10^3 is about the distance it falls in ten seconds.

PS: I used the well known SUVAT equations to find these answers. Look up SUVAT equations on the web and you'll find a complete explanation what they are. You should know them cold for HS physics. You'll see them over and over again.