'Density' is defined as (mass) / (volume). You need enough information to be able to measure or calculate the mass and the volume of the object.
True True False True False False True I hope I helped on the first few
The answer is
Pitch of the buzzer increased (higher tone) as it moves towards the observer
The electric field is always perpendicular to the surface outside of a conductor. TRUE
<span> If an electron were placed on an electric field line, it would move in a direction perpendicular to the field. FALSE, it would move in an anti-parallel direction because its charge is negative </span>
<span>Electric field lines originate on positive charge and terminate on negative charge. TRUE ; but they can also go to infinity </span>
It is possible for two electric field lines to cross each other.
<span> Usually FALSE; though technically possible at special points where field is zero. </span>
If an electron and a positron were in the presence of a very strong electric field, they would move away from each other.
<span> TRUE; one is positive, and one is negative. If the field is strong enough, the action of the field will overcome the mutual attraction between them </span>
It is not possible for the electric field to ever be zero. FALSE: it IS possible, inside a conductor for instance
If a proton were placed on an electric field line, it would move in a direction anti-parallel to the field.
<span> FALSE: being positive, it would move in the SAME direction as the field</span>ic
