Answer:
1373.4 N/m
Explanation:
Hooke's law states that the extension of a spring and force are related by the expression, F=kx where k is spring constant, x is extension of spring and F is the applied force. Making k the subject of the formula then

Also, F=gm hence the above formula is modified as

Taking g as 9.81 m/s2 , x as 0.5 m and m as 70 kg then

Momentum is related to mass. In fact, it's directly proportional to mass.
Answer:
The value of each charge is 4.22 x 10⁻⁵ C
Explanation:
Given;
distance between the two identical charges, d = 2 m
the force of repulsion between these two charges, F = 4N
Apply Coulomb's law;

Therefore, the value of each charge is 4.22 x 10⁻⁵ C