Page 72 - Physics

Physics for Secondary Schools

Neutron

Nucleus Nucleus

Neutron

Neutron
Nucleus Nucleus
Nucleus
Nucleus

Fusion Fission Neutron

Figure 3.7: Nuclear fusion and fi ssion

The strong force has the following Exercise 3.1
properties:
(a) It is basically an attractive force. 1. Is an astronaut in space completely

(b) It is a short-range force (operates weightless? Explain your answer.
in a distance ranging from 0.7 2. How much do you weigh on the earth?
femtometre (fm) to 2.5 femtometre Would you weigh the same on the moon?
(fm)). Explain your answer.
(c) It is a non-central force (does not 3. Estimate your mass on the earth. If you
originate from the centre). are standing on the moon, do you think
(d) It is stronger than gravitational your mass on the moon will be the same?
force. Discuss your answers.

(e) It does not depend on charges of 4. Find the mass of a student who has a
objects.
weight of 600 N.
Weak force

This is a nuclear force which appears Contact forces
only in a certain nuclear process. The These are forces which require physical contact
following are properties of the weak to occur. They include: stretching, compression
force: or restoring, attraction, repulsion, torsion,
(a) It is much stronger than the friction, viscous forces, and air resistance.
gravitational force but weaker than These forces result from the interaction of
the strong and electromagnetic fundamental forces. Each force has particular
forces.
(b) It acts on a small range of about effects on the objects to which it acts. Hence,
0.001 fm to 0.01 fm. these forces are discussed based on their effects.

66
Student’s Book Form One

Physics Form 1 Final.indd 66 16/10/2024 20:56