Can someone please answer ASAP. I only had 3 minutes to answer this question ‍♀️. (No FAKE LINKS!!)

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?

Cole says the distance between points (-5,0) and (0,-5)is 5 units. is he correct? explain why or why not.

Mrs. piazza invested 8000 in a certificate of deposit that pays 3% simple interest for 4 years. how much will be in mrs. piazza's account at the end of 4 years