Orbital motion & satellites

Telescopes are used to look at distant objects.

Some telescopes use lenses to form an image.

Figure 5 shows two parallel rays of light incident on a lens in a telescope.

The principal focus of the lens is labelled F.

What type of lens is shown in Figure 5 ?

Complete the ray diagram in Figure 5.

The James Webb Space Telescope can detect electromagnetic radiation beyond the visible spectrum.

The shortest wavelength of electromagnetic radiation that can be detected by the James Webb Space Telescope is 0.60 m.

speed of electromagnetic radiation = 3.0 × 10⁸ m/s

Calculate the frequency of electromagnetic radiation that has a wavelength of

Use the Physics Equations Sheet.

Complete the sentence.

Electromagnetic radiation detected from distant galaxies is red-shifted.

This means that the electromagnetic radiation shows an increase in

Why is the electromagnetic radiation from distant galaxies red-shifted?

Tick () one box.

The James Webb Space Telescope has detected electromagnetic radiation from many different galaxies.

Electromagnetic radiation from one of the galaxies detected shows the greatest red-shift ever observed.

What conclusion can be made about the distance to this galaxy?

The James Webb Space Telescope is an artificial satellite that orbits the Sun at a constant speed.

Explain why the velocity of the satellite changes as it orbits the Sun.

Figure 17 shows the Hubble Space Telescope orbiting the Earth.

What name is given to an object that orbits a planet? Tick (✓) one box.

The Earth exerts a gravitational force on the Hubble Space Telescope. Draw an arrow on Figure 17 to show the gravitational force.

Figure 18 shows how the distance travelled by the Hubble Space Telescope during its orbit changes with time.

The gradient of the line in Figure 18 gives the speed of the Hubble Space Telescope. Determine the speed of the Hubble Space Telescope. Give your answer in km/s.

The Hubble Space Telescope can detect the visible light spectra from distant galaxies. The visible light spectra from stars and galaxies include dark lines at specific wavelengths. Figure 19 shows the visible light spectra from the Sun and three galaxies.

Which galaxy is moving away from the Earth the fastest? Tick (✓) one box.

Which galaxy is the furthest away from the Earth? Tick (✓) one box.

New scientific observations indicate that many galaxies rotate too quickly for the known mass of the stars they contain. Why is it important that new scientific observations are peer reviewed? Tick (✓) one box.

Figure 15 shows the Hubble Space Telescope orbiting the Earth.

What name is given to objects that orbit a planet?

A space telescope uses microwaves to communicate with the Earth. A microwave has a wavelength of 12.5 cm. The speed of microwaves through space is 3.0 × 10⁸ m/s. Calculate the frequency of the microwave. Use the Physics Equations Sheet. Give your answer in standard form.

Explain the effect of the Earth’s gravitational force on the motion of the Hubble Space Telescope.

The Hubble Space Telescope can detect visible light from distant galaxies. The visible light spectra from stars and galaxies include dark lines at specific wavelengths. Figure 16 shows the visible light spectra from the Sun and two galaxies.

Explain what conclusions can be made about galaxies A and B.

The Sun is at the centre of our solar system.

What type of object is the Sun?

What is the name of the galaxy our solar system is part of?

Tick (✓) one box.

Table 2 gives information about some of the moons in our solar system.

What is a moon?

A student researched the radius of some planets in the solar system.

radius of largest dwarf planet = 1190 km radius of smallest planet = 2440 km

The student made the following conclusions:

1. dwarf planets are always smaller than moons

2. planets are always bigger than moons.

Give one reason why each of the student’s conclusions is wrong.

Use the data given above and in Table 2.

The Earth’s Moon and the International Space Station both orbit the Earth.

Give one other similarity and one difference between the orbit of the Earth’s Moon and the orbit of the International Space Station.

Very few people have been to the International Space Station.

Suggest one reason why very few people have been to the International Space Station.

Our solar system includes the Sun, planets and moons.

Complete the sentence. Choose the answer from the box.

Planets orbit the Sun. What force causes planets to orbit the Sun?

Table 2 shows data about five planets.

How does the mean surface temperature of the planets in Table 2 change as the mean distance from the Sun increases?

Predict the mean surface temperature of Jupiter (X) in Table 2.

Five of the planets in the solar system are given in Table 2. How many other planets are there in the solar system? Tick (✓) one box.

Our Moon is a natural satellite. Why is the Moon classified as a satellite? Tick (✓) one box.

How are planets and moons similar? Tick (✓) two boxes.

The diameter of the Earth is 13 000 km. The diameter of the Sun is 110 times greater than the diameter of the Earth. Calculate the diameter of the Sun.

A satellite is in a circular orbit around the Earth. Figure 14 shows the velocity of the satellite at two different positions in the orbit.

Figure 14

Explain why the velocity of the satellite changes as it orbits the Earth.

Figure 15 shows how the length of a satellite orbit depends on the height of the satellite above the Earth’s surface.

Figure 15

A satellite orbits 300 km above the Earth’s surface at a speed of 7.73 km/s. Calculate how many complete orbits of the Earth the satellite will make in 24 hours.

In 1772, an astronomer called J Bode developed an equation to predict the orbital radii of the planets around the Sun. Table 3 shows Bode’s predicted orbital radii and the actual orbital radii for the planets that were known in 1772. Table 3

The predicted data can be considered to be accurate. Give the reason why.

J Bode used his equation to predict the existence of a planet with an orbital radius of 2940 million kilometres. The planet Uranus was discovered in 1781. Uranus has an orbital radius of 2875 million kilometres. Explain why the discovery of Uranus was important.