1. What objects in this picture are in motion? 2.What is the unbalanced force in this picture?

3. What happened to the sledder in this picture?

Sled going down is in motion
Sled hitting rock is unbalanced
He flew because the of the sudden stop threw them off

Iodine-131 has a shorter half-life than cobalt-60.

Explanation:

We are given;

Half of a cobalt-60 sample decays after 5.26 years Half of an Iodine-131 sample decays after 8.1 days

We are supposed to explain the difference between the two instances;

We need to define half life;

Half life is the time half of a given sample takes to decay leaving the other half of it.Therefore;If half of a cobalt-60 sample decays after 5.26 years then the half life of cobalt-60 is 5.26 years.On the other hand, if half of an Iodine-131 sample decays after 8.1 days, then the half life of Iodine-131 is 8.1 days.We can therefore, conclude that, Iodine-131 has a shorter half-life than cobalt-60.