Expirement 3- Finding the value of g (gravity)

Aim?

To determine the acceleration due to gravity, , using a free-fall apparatus and scaler timer.

Equipment?

Free-fall apparatus, steel ball, scaler timer, connecting leads, retort stand and clamp, metre stick.

Method?

Set up the apparatus and check the timer works correctly.

Measure the distance fallen, , using a metre stick.

Reset the timer and release the ball, starting the timer simultaneously.

Record the fall time, .

Repeat at least three times and use the smallest time.

Repeat for different heights .

What is X Axis on graph?

X axis: t*2(s*2) Time 2(seconds*2)

What is Y Axis on graph

Y axis: s (m)

s= displacement measured in metres

How to find slope? and gravity?

When using graph:

y2-y1/ x2-x1, straight line through origin = Slope

2 x Slope= Gravity (around ~ 9.8) ms*-2

Or slope = s/t*2

How time interval t is measured?

Time from when the metal ball is released to when it hits the pressure pad.

Repeat 3 times for the smallest t value

Use this value for t

Sources of error/ Precautions

Avoid parallax when measuring .

Use a small, smooth, dense steel ball to minimise air resistance.

Use the smallest recorded time for each height because timing errors tend to increase .

How to minimise the effect of air resistance?

Use a high density small diameter metal ball

Keep drop height from relatively low height