Question 10
FA teacher uses a balloon to model the expanding Universe.
She draws three dots, X, Y and Z, on the balloon and then blows it up.
The Figure shows the balloon before and after it is blown up.
Figure
The Table shows the distances between the dots before and after the balloon is blown up.
Table
| Dots | Distance before in cm\text{cm}cm | Distance after in cm\text{cm}cm |
|---|---|---|
| X to Y | 2.0 | 4.0 |
| X to Z | 5.0 | 10.0 |
a.[1]
State what the dots on the balloon represent.
b.[1]
Calculate the increase in the distance between X and Z.
c.[2]
The teacher takes 10 s to blow up the balloon.
Calculate the average speed at which dot Z moves away from dot X.
d.[2]
Explain how the balloon model shows that more distant galaxies move away from us faster.
e.[1]
Give one way in which the balloon is not a good model of the Universe.
7.2 The Universe and red-shift Questions
94 exam-style questions on Edexcel GCSE Physics 7.2 The Universe and red-shift, covering 7.2.1 Big Bang and Steady State theories, 7.2.2 Evidence for the Big Bang, 7.2.3 The Doppler effect and red-shift, 7.2.4 Red-shift as evidence for an expanding Universe, and 7.2.5 The CMB and the accepted model. Each one has a worked solution and a mark scheme showing where the marks go.