Answer:
2
Explanation:
helium has 2 protons and 2 neutrons
Answer:
Match with A) Single fixed pulley, B) block & tackle, or C) single moveable pulley
changes the direction of effort; input is 1/2 the distance; or system of pulleys
Explanation:
3. A loudspeaker works because of the “motor effect” meaning electricity and a magnetic field cause movement.
4. A direct current will cause momentary movement in one direction only. For the speaker to produce sound you would need alternating current which makes the cone vibrate back & forth.
Friction is an example of thermal energy. As the tiny heat particles move, more warmness is made from the friction.