Finding velocity from table?

Question

I'm doing a prac and making a graph from the information that I have obtained and i'm not sure if i'm getting the right velocity.

This is the information I have collected...

Time (s)

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

and

Vertical Distance (m) from ground

0.8712

0.8175

0.7538

0.6759

0.5868

0.4824

0.3698

0.2495

0.1256

0

For the velocities I have done like, for the second one (0.8175-0.8712)/0.05 and then I have done that, so the velocity values I have gotten are

1.074

1.274

1.558

1.782

2.088

2.252

2.406

2.478

2.512

But I havent gotten a velocity for the first ball... I hope I'm making sense..

Can someone please tell me if I'm doing this right or what I should be doing?

Thanks guys

Answer 1

You velocities look correct to me.  what do you mean first ball?

Answer 2

What do you mean by first ball? Does the experiment involve throwing a ball vertically up in the air and measuring its position at different times?

You have correctly calculated velocities at different intervals.

But what do you mean by first ball? Moreover, what is the purpose of this experiment? Suppose you find velocities. Then what will you do after that? Is the purpose to find acceleration due to gravity or something else?

The velocities that you have calculated are the average velocities during different intervals. The intervals are

0.05 to 0.1

0.1 to 0.15

0.15 to 0.2

0.2 to 0.25

0.25 to 0.3

0.3 to 0.35

0.35 to 0.4

0.4 to 0.45

0.45 to 0.5

Is the above what you wanted to do? What exactly do you want to calculate from the graph?

And do you know the height of the table top from the ground?

If you want to know the velocity at the beginning, then you need to know the height of the table top from the ground i.e. the height from which the ball starts falling.

Suppose the height is H

Distance from ground at t = 0 is H

Distance from ground at t = 0.05 s is 0.8712

Velocity = (H - 0.8712)/0.05

This is the average speed during the interval 0 to 0.05 s

Answer 3

you are doing it right, you should have 9 velocities since

v= change in distance/change in time= (X2-X1)/(t2-t2)