Physical science I need help on how to do the math

Name :Physical Science Forces : Homework # 11 ) What will be the final velocity of an object that falls from rest , if it falls for 5 seconds ?2 ) How many seconds of time does it take an object dropped from rest to reach a final velocity of30 meters / second ?"3 ) What will be the final speed of an object that's dropped from rest if it falls for 4 seconds ?4 ) How many seconds are needed for an object dropped from rest to reach a final velocity of 98meters / second ?5 ) Two students are pushing on a box in the same direction , and one other student is pushing on abox in the opposite direction . What is the net force on the box if each pushes with - a force of 50 N ?5 ) You are an international spy and just jumped off an airplane to escape your pursuers . If thedownward force of gravity and the upward force of air resistance on you are both 350 N , are youstill falling toward the ground ? Explain .7) You are trying to push a couch from one corner of your room to another . You push , but thecouch doesn't move . What force prevents you from pushing the couch across the room ? Explainhow it works .8 ) Why do feathers , leaves , and pieces of paper fall more slowly than pennies , acorns , and apples ?!