If a nuclear medicine is found to be 1/32nd its original strength, how many half-lives have passed since the medicine was created in the laboratory?

5 half-lives

Explanation:

Original value Half-lives

1                           0

1/2                         1

1/4                         2

1/8                         3

1/16                        4

1/32                      5

This means it takes 5 half-lives after 1/32 of the original strength is found

Explanation:

Step 1: Data given

1/32 of the original strenght will remain after X time

Step 2: Calculate Number of half-life times

Let x be the number of half-lives.

For 1/32 left

2^-x = 1/32

x = 5

This means it takes 5 half-lives after 1/32 of the original sample is found

We can control this like:

After 1 half- life half of the sample is left = 1/2 of the original strength is found

After 2 half-lives, there will remain 1/4 of the original strength is found

After 3 half-lives, there will remain 1/8 of the original strength is found

After 4 half-lives, there will remain 1/16 of the original strength is found

After 5 half-lives,there will remain 1/32 of the original strength is found

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied