First one, insulator. Second one, conductor.
Answer:
Mechanical energy
Explanation:
If an object does not have any momentum, then it doesn't have mechicanl energy.
If it takes the swing 2 seconds to complete one cycle, then
that's the period of its motion ... 2 seconds.
The frequency is the reciprocal of the period ... 1/2 Hz.
('Hz' means 'per second'.)
Thumbtacks have a flat top which gives you a bigger area to push on, and the end is tapered and sharp to make it easier to push it into a wall, etc.
Answer:
Explanation:
Given that
As both charges are negative so there exist force of repulsion in direction as shown in figure.
Angle at which force F12 is acting is
Force exerted on charge -2e is equal in magnitude to F12 but is in opposite direction