The back-and-forth movement of electrons is called alternating current. Electrons go back and forth, the direction of their path alternates from one direction to another.
the movement of electrons in one direction is called direct current. The electrons move in a direct, single path without changing directions.
Answer:
Explanation:
for baseball
(a) Let the mass of the baseball is m.
radius of baseball is r.
Total kinetic energy of the baseball, T = rotational kinetic energy + translational kinetic energy
T = 0.5 Iω² + 0.5 mv²
Where, I be the moment of inertia and ω be the angular speed.
ω = v/r
T = 0.5 x 2/3 mr² x v²/r² + 0.5 mv²
T = 0.83 mv²
According to the conservation of energy, the total kinetic energy at the bottom is equal to the total potential energy at the top.
m g h = 0.83 mv²
where, h be the height of the top of the hill.
9.8 x h = 0.83 x 6.8 x 6.8
h = 3.93 m
(b) Let the velocity of juice can is v'.
moment of inertia of the juice can = 1/2mr²
So, total kinetic energy
T = 0.5 x I x ω² + 0.5 mv²
T = 0.5 x 0.5 x m x r² x v²/r² + 0.5 mv²
m g h = 0.75 mv²
9.8 x 3.93 = 0.75 v²
v = 7.2 m/s
Mercury's natural state is where the atoms are close to each other but are still free to pass by each other. In which state(s) could mercury naturally exist?
Liquid is the answer
4. a poor insulator
If rest other things are kept constant or unchanged then a good conductor can be termed as a poor insulator.
Answer:
1. 571.43m/s
2. 142.9m and 342.9m
Explanation:
1.Take the difference in time.
1.2-0.7=0.7 seconds
Take the distance between them and divide with differnce in time.
400÷0.7=571.43 seconds.
2.Take the time of the two men and divide by two.
0.5÷2= 0.25 secs
1.2÷2= 0.6 secs
multiply each with the velocity.
0.25×571.43=142.9m
0.6×571.43=342.9m
