Pls explain with proper steps

1. A farmer moves along the boundary of a square field of side 10m in 40s. What will be the
magnitude of displacement of the farmer at the end of 2 minutes 20 seconds?
2. What is the acceleration of a body moving with constant velocity?
3. Is it possible for a body to be accelerated, if its speed is constant. If so, give an example.

Question 5 spring semester final exam math evaluate

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?

Vinny is interviewing for a job.he wants his take home pay to be at least $42,000.what is the least salary he can earn if he pays 25% income tax?