Answer:
In most materials, atoms are arranged in such a way that the magnetic orientation of one electron cancels out the orientation of another
If the machine is 100% efficient, then its
Mechanical Advantage is (450/50) = 9 .
If the machine is less than 100% efficient,
then the MA is more than 9 .
Answer:
V1 =8.1 m/s
Explanation:
height at highest point (h2) = 4.1 m
height at lowest point (h1) = 0.8 m
acceleration due to gravity (g) = 9.8 m/s^{2}
from conservation of energy, the total energy at the lowest point will be the same as the total energy at the highest point. therefore
mgh1 +
= mgh2 + 
where
- speed at highest point = V2
- speed at lowest point = V1
- mass of the girl and swing = m
- at the highest point, the speed is minimum (V1 = 0)
- at the lowest point the speed is maximum (V2 is the maximum speed)
- therefore the equation becomes mgh1 +
= mgh2
m(gh1 +
) = m(gh2)
gh1 +
= gh2
V1 = 
now we can substitute all required values into the equation above.
V1 = 
V1 = 
V1 =8.1 m/s
Answer:
The tension increases to four times its original value.
Explanation:
v = Velocity
r = Radius
m = Mass of stone
The centripetal force is

The tension will balance the centripetal force



The new tension will be 4 times the old tension