Cambridge Primary (1-6). Stage 6. Science. Learner's Book - Unit 5: Forces and electricity

The picture shows an astronaut standing on the Moon.
Discuss these questions with a partner.



What is a satellite?

The picture shows an astronaut standing on the Moon.
Discuss these questions with a partner.



Why is the Moon a natural satellite rather than an artificial satellite?

The picture shows an astronaut standing on the Moon.
Discuss these questions with a partner.



How does the Moon stay in orbit around the Earth?

The picture shows an astronaut standing on the Moon.
Discuss these questions with a partner.



Do you think the astronaut weighs the same on the Moon as they do on Earth? What unit will their weight be measured in?

Was the nurse scientifically correct to say that the baby weighs 3.6 kg?
If not, what should she have said?

Complete the following sentences using the words weight and mass:
An object’s __________ remains the same wherever it is.
An object’s __________ depends on the force of gravity.

Will the astronaut in the picture have the same mass on the Moon as they do on Earth?

How will the astronaut’s weight change on the Moon?

Explain why his weight changes.

With a partner, discuss why you think astronauts who walk on the Moon have to wear very heavy suits and boots.
Do you think they can drink a glass of water on the Moon?

Work in groups of two or four.

You will need:
a scale to measure mass and a forcemeter to measure weight (or a device that measures both mass in grams and weight in newtons), a plastic carrier bag, objects of different masses to measure

1 Draw a table to record your measurements. You will need a column for the name of the objects, a column for the mass of the objects in grams and a column for the weight of the objects in newtons.
2 Place each of the objects on the scale, one at a time. Record your measurements in your table.
3 Hold the forcemeter by the top ring. Put each of the objects in the plastic bag, one at a time. Hang the bag on the bottom hook of the forcemeter. Record your measurements in your table.

Compare the readings on the measuring scale with the readings on the forcemeter.
What pattern do you see?

Did any of your measurements not fit this pattern? If so, repeat these measurements.

Complete this sentence to make a conclusion about the mass and weight of an object measured on Earth:
One kilogram of __________ has a weight of __________ on Earth.

Imagine you had done this activity on the Moon.
Would the mass of the objects be the same or different to those measured on Earth? Explain why.

Imagine you had done this activity on the Moon.
Would the weight of the objects be the same or different to those measured on Earth? Explain why.

What causes weightlessness?

Which force causes the International Space station to fall towards Earth?

List three ways that weightlessness affects astronauts.

How do astronauts manage to work outside the spacecraft?