Please answer quickly!

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?

Find the solution on the interval [0, 2pi)

Theo found the driving distance from glacier national park to yellowstone park to be 448 miles. theo used a map that had a ratio of 5cm/300mi. how many centimeters is the distance on the map? round to the nearest unit if necessary. 4 centimeters 7 centimeters 64 centimeters 90 centimeters