Physics: Translational Motion

[basketballakev]

Hey you guys I don't why I can't get this simple problem but here it goes..

What is the average speed during the first 10 seconds of free fall for an object that starts at rest?

A. 10 m/s
B. 25 m/s
C. 50 m/s
D. 100 m/s

So i used the equation Vf = Vi + a(Delta t) and Vi = 0 since it is at rest.
Thus Vf = a(Delta t) = 10(10) = 100 m/s but the answer is C. What am I doing wrong!? Thanks a lot guys.

---

Members don't see this ad.

 

[cwfergus]

You basically just told us. Vi=0, vf=100. what is the average speed for the free fall object? vave=50

 

[hector219]

you solved for FINAL, not average, velocity. The average velocity is halfway between the initial and final.

 

[Phlame217]

quoting exam krackers, think of the initial and final being on a line such as:

0m/s----------------------------X--------------------------100m/s

X is the half way which equals the average, only if there is constant accelleration though.

therefore x = 50 m/s