A straight highway leads to the foot of a tower. A man standing on its top observes a car at an angle of depression of 30, which is approaching the foot of tower with a uniform speed. 6 seconds later, the angle of depression of the car becomes 60. Find the time taken by the car to reach the foot of tower from this point.

Aplane flies around trip to philadelphia it flies to philadelphia at 220 miles per hour and back home with a tailwind at 280 miles per hour if the total trip takes 6.5 hours how many miles does the plane fly round trip

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected