Earth & Space (OCR GCSE Physics A (Gateway))

A student looks at two identical metal spoons, A and B.

Spoon A was placed in hot water at 70°C.

Spoon B is at 20°C.

Which spoon emits the most radiation?

Tick (✓) one box.

Explain your answer.

Explain why both spoons look identical to the student, even though they are at different temperatures.

Higher Tier Only

 The Earth contains a crust, mantle and core as shown in Fig. 22.1.

Fig. 22.1

Table 22.1 gives some data about seismic waves and the Earth.

Table 22.1

Describe what information the data in Table 22.1 gives about the structure of the Earth.

In your answer you should explain any trends in the data in Table 22.1.

Edwin Hubble discovered that all distant galaxies were moving away from the Earth.

Explain how he could tell that all distant galaxies were moving away from the Earth.

This graph shows how the speed of a galaxy changes with distance from the Earth.

i) Use data from the graph to show that the speed of the galaxy is proportional to the distance from the Earth.

ii) Explain how data from the graph provides evidence for the Big-Bang.

Before Edwin Hubble could publish his results, his work was peer reviewed.

Suggest why peer review is important.

The parsec (pc) is a unit used for measuring large distances in the Universe.

i)A galaxy is at a distance of 82 Mpc from the Earth.

Use the graph to determine the speed of this galaxy.

Give your answer in metres per second (m/s).

Speed = ................................................... m/s

ii) Calculate the time it takes for the galaxy to travel 2.53 × 10²⁴ m.

Use your answer to 22(d)(i) to help you.

Time = ........................................................ s

Scientists collect evidence from the universe and develop theories to explain their observations.

The diagram shows three absorption spectra showing red shift.

The white arrows show the relative position of the same band in the absorption spectra of a distant galaxy, a nearby galaxy and a star.

Using your knowledge of red shift, describe how the information in the diagrams supports the idea of the Big Bang model.

Higher Tier Only

State two features of a satellite in a polar orbit?

Suggest a use for a satellite in a polar orbit.

Higher Tier Only

An artificial satellite (X) is kept in a stable circular orbit around a planet by a centripetal force caused by gravity.

i) Explain how the velocity of a satellite is constantly changing whilst its speed remains the same when it is in orbit.

ii) The satellite is remotely controlled from Earth.

The scientists want the satellite to move slower.

What effect will this change in speed have on the height of its orbit?

Explain your answer.