- #1

Barclay

- 208

- 1

## Homework Statement

A student investigates the motion of a trolley as it rolls down a ramp ... a data logger records the time the beam was broken for and uses this to calculate the speed of the trolley.

Experiment results are:

Height of ramp (cm) / Momentum of trolley at the bottom

15 / 1.1

20 / 1.3

25 / 1.5

30 / 1.6

35 / 1.8

40 / 2.0Q1. Draw a graph of the results with height on x-axis and momentum on y-axisQ2. Describe the pattern of the graph.Q3. Do the data points on the graph suggest that the line should go through the origin?

Q4. Using ideas about momentum, explain whether you would expect the line to go through the origin.

## Homework Equations

[/B]

momentum = mass x velocity

## The Attempt at a Solution

[/B]

Q1 - done that

Q2. It looks like a straight line ... well more or less (allowing for experimental error). I say as the height of the ramp increases the momentum increases.

The book answer also says "as the height of the ramp increases the momentum increases" but then says "It is not proportional". I do not understand that. A straight line, I thought means proportionality

Q3. Y-axis is cut at 0.6 kg m/s ... this is correct according to the book

Q4.

I say YES the line should pass through the origin because at the beginning velocity is ZERO so momentum is ZERO from momentum = mass x velocity but the line cuts the y-axis at 0.6 kg m/s.

The book says the student should make more measurements between 0 cm and 15 cm but friction slows the trolley down preventing this.

My main confusion is why the graph looks like a straight line but the book suggests it should be curved and pass to ZERO