Answer: 
Step-by-step explanation:
Given
The expression is

Use identity 
Apply identity

Answer:
10
Step-by-step explanation:
Answer:D
Step-by-step explanation:
Answer:
8516 meters
Step-by-step explanation:
Answer: it's a '40.0-kg object, not a 40.4-kg object, which would explain why the answer is different.
Step-by-step explanation: