Diann wants to see if heat causes happiness. she asks 100 participants to come to the laboratory, and as they walk in, she asks each person to choose a warm booth or a cool booth. on the basis of their choices, participants spend 20 minutes in one or the other booth before rating their levels of general happiness. what's wrong with diann's experiment?

Two objects of different mass start from rest, are pulled by the same magnitude net force, and are moved through the same distance. the work done on object 1 is 900 j. after the force has pulled each object, object 1 moves twice as fast as object 2. how much work is done on object 2?

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e

The force needed to overcome static friction is usually less than that needed to overcome kinetic friction.true or false?