Page 68 - text book form physics kssm 2020

Results:

Table 2.9
Before collision After collision
Total Trolley A and Total
momentum trolley B momentum
Trolley A Trolley B
v
1
u
(cm per (cm per
1 2 2 1 1 2 2 1 2 1 2
m m u m u + m u m + m (m + m )v
10 ticks) 10 ticks)
1 1 0 2
1 2 0 3
2 1 0 3
3 1 0 4

Discussion:
1. What is a friction compensated runway?
2. Compare the total momentum before and after collision.
3. Is the total momentum conserved? Explain your answer.

In Activity 2.11, you may find that the total momentum before and after collision differs
slightly. This difference is due to external forces such as friction that cannot be compensated
completely.

Before collision After collision

A B A B
u u v v
1 2 1 2

m m m m
1 2 1 2

Figure 2.49 A system of two objects before and after collision
Figure 2.49 shows a system of two objects before and after collision. The Principle of
Conservation of Momentum states that the total momentum before collision is equal to the total
momentum after collision if no external force is acting on it.

m u + m u = m v + m v
1 1 2 2 1 1 2 2

62 2.5.2
62
2.5.2