Which event is an example of a contact force? a. a leaf falling from a tree b. a nail being attracted to a magnet c. an electric charge jumping from a sweater to a person d. a person pulling a sled

Agas in a balloon at constant pressure has a volume of 160 ml at -125*c. what is its volume at 29.0*c?

Consider the nuclear equation below. 239/94 pu—-> x+ 4/2 he. what is x?

The twister and runaway train are two coasters at the same amusement park. both coasters start at the same height. the coaster for the twister is twice the mass of the coaster for the runaway train. which roller coaster has greater gravitational potential energy at the start of the ride?