Help please I need an answer asap

Find the value of the cosine for angle a

Kyle and elijah are planning a road trip to california. their car travels 3/4 of a mile per min if they did not stop driving, how many miles could kyle and elijah drive in a whole day? ? 1 day = 24 hours. plzzz i will give you 100 points

Is the power produced directly proportional to the wind speed, give reasons for your answer?