A farmer bought 30 feet of fencing to build a circular pen for his pigs. What is the diameter of the pen he can build with 30 feet of fencing?
The farmer also needs to buy a certain type of seed for the grass in the pen. Each bag of seed can cover 50
feet of land. How many bags of seed will the farmer need to buy?

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?