Here is the answer for the first one....

1. Take any three coins and weigh them against any other three coins. If they weigh the same, the heavy coin is one that is not weighed or left out;

If one set of three coins is heavier than the other, take two coins from the heavier set and weigh them against each other. If one of those is heavier than the other, the heavy coin has been identified. If those two coins weigh the same, the heavy coin is the third coin from that set of three.

2. Pants

3. Dictionary

4. Footwear