This may be the answer,hope it helps
Answer:
C. 303,000 Joules
Step-by-step explanation:
1. use abcos(theta)
a=50
b=7000
theta=30 degrees
2. (50)(7000)cos(30)=303,000
Hello, please consider the following.

For the second we will need to put on the same denominator.

Thank you.