HElp please need help

Your best friend told you that last week scientists disco y that las vegas is responsible for abrupt climate changes. which do you think is best way to research that recent discovery? an encyclopedia usgs internet site a book in the library your best friend’s parents for your ! ❤️

Which of the following functions corresponds to the above sinusoid? a. 10 cos πx - 5 b. -5 sin x - 5 c. -10 cos πx/2 - 0.5 d. 10 sin πx - 5

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?