Question: The force between a pair of 0.005 C is 750 N. What is the distance between them?
Answer:
17.32 m
Explanation:
From coulomb's Law,
F = kqq'/r²........................... Equation 1
Where F = Force between the force, q' and q = both charges respectively, k = coulomb's constant, r = distance between both charges.
make r the subject of the equation above
r = √(kqq'/F)..................... Equation 2
From the question,
Given: q = q' = 0.005 C, F = 750 N
Constant: k = 9.0×10⁹ Nm²/C².
Substitute these values into equation 2
r = √(9.0×10⁹×0.005×0.005/750)
r = √(300)
r = 17.32 m.
Hence the distance between the pair of charges = 17.32 m
Answer:
c. 12,500
Explanation:
Original number of atoms = 100,000 atoms
Half- life = 10min
Unknown:
The number of atoms that will remain after 10min = ?
Solution:
The half - life is the time taken for half of a radioactive substance to decay by half.
Time taken Number of atom half life
10min 100000 _
20min 50000 1
30min 25000 2
40min 12500 3
Answer:
10 seconds
Explanation:
If the height is modeled by the function 
, then the seconds it takes to reach the water (when the height equals 0) is modeled by the following.
Divide 2500 g by 500 cc. The quotient is 5 g/cc ... the density.
Gravity adds 9.8 m/s to the downward speed of a falling object every second. (On Earth.)
In 7 seconds, gravity adds (7 x 9.8 m/s) = <em>68.6 m/s</em> to the downward speed of a falling object.
(IF air resistance has no effect on the object.)
