Pre calculus Plzzz help other wise I will fail I can pass with these 4 questions please I beg you

Can someone me my sister? she is in third grade. 50 points and brainlist! ones that are not answered. plz and thx!

The circumference of a redwood tree trunk is 20π ft, and it is 100 ft tall. what is the approximate volume of the redwood tree trunk? 1,000π ft3 10,000π ft3 4,000π ft3 40,000π ft3

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?