5
if zero falls between two significant numbers it becomes significant.
Answer:
1.
Firstly removing off one strip and it leaves electrons behind, so the strip becomes positively charged.
2. The roll however is not negatively charged because it is "earthed " by the hand holding it, thus excess negatives repel each other away through the hand.
3.Tearing off the next strip and once more it leaves electrons behind, the new strip is also positively charged and will repel the first strip.
4. Then, tear two strips apart and one will leave electrons behind on the other. Meaning that one strip is positive and the other is negative and they will attract each other.
Answer:
The charge of an element is equal to the number of protons minus the number of electrons. The number of protons is equal to the atomic number of the element given in the periodic table. The number of electrons is equal to the atomic number minus the charge of the atom.
Explanation:
Answer:
v ≈ 7900 m/s
Explanation:
centripetal force will equal gravity force
mv²/R = mg
v²/R = g
v² = Rg
v = √(Rg)
v = √(6.4e6(9.8))
v = 7.91959...e+3
v ≈ 7900 m/s
of course, at those velocities and that deep into the atmosphere, the satellite would quickly burn up, slow down, and cause tremendous damage to buildings etc. with the sonic boom shock wave. It would also have to avoid a lot of mountains as 4000 m is not that high.
Explanation:
F=m(v-u)/t
F=2N
m=2kg
t=2s
2=2(v-u)/2
cross multiply
2*2=2(v-u)
4=2(v-u)
4/2=v-u
v-u=2m/s
v-u is the change is velocity.
