Jack travels to work on the eastern freeway. he notices that the difference in time between if he drives 5 mph below the speed limit and if he drives 15 mph below the speed limit is 2 minutes. given that the distance for which he uses the freeway is 10 miles, find the speed limit of the freeway. 55 mph 65 mph 60 mph 45 mph

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?