Atruck with a heavy load drove from boston to new york at 45 mph. after unloading, it returned from new york to boston at a speed of 65 mph. what was its average speed for the whole trip?

The difference between two numbers is one. three times the larger number minus two times the smaller number is 9. what are the two numbers

Maddie's rectangular kitchen has an area of 10 square yards and a length of 3 3/4 yards.how many yards wide is maddie's kitchen?

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?