For numbers 2 and 3, which one is compression and which one is rarefaction?

Will you chech and finish these for me, because i am stumped with them.

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec

(01.02 mc) nicole pushes her bike up a hill. overhead, the sun exerts a gravitational force on earth. which statement is true about the bike and earth? they both experience contact forces. they both experience non-contact forces. the bike experiences a non-contact force and earth experiences a contact force. the bike experiences a contact force and earth experiences a non-contact force. they both experience non-contact forces.