What type of rock(sedimentary, igneous, or metamorphic) would you expect to find at the
border between the South American Plate and the African Plate? Why?

Could someone . i have tried to solve myself but my calculation is off

If a balloon is taken outside on a very cold day, what will occur?

Under the action of a constant force an object accelerates at 7.8 m/s2. what will the acceleration be if (a) the force is halved? (b) the object's mass is halved? (c) the force and the object's mass are both halved? (d) the force is halved and the object's mass is doubled?