Explanation:
At the instant of release there is no force but an acceleration of a, this means the ball is falling freely under the force of gravity. Then the acceleration would be due to force of gravity and acceleration a = g =9.81 m/s^2.
g= acceleration due to gravity
This electric force calculator will enable you to determine the repulsive or attractive force between two static charged particles. Continue reading to get a better understanding of Coulomb's law, the conditions of its validity, and the physical interpretation of the obtained result.
How to use Coulomb's law
Coulomb's law, otherwise known as Coulomb's inverse-square law, describes the electrostatic force acting between two charges. The force acts along the shortest line that joins the charges. It is repulsive if both charges have the same sign and attractive if they have opposite signs.
Coulomb's law is formulated as follows:
F = keq₁q₂/r²
where:
F is the electrostatic force between charges (in Newtons),
q₁ is the magnitude of the first charge (in Coulombs),
q₂ is the magnitude of the second charge (in Coulombs),
r is the shortest distance between the charges (in m),
ke is the Coulomb's constant. It is equal to 8.98755 × 10⁹ N·m²/C². This value is already embedded in the calculator - you don't have to remember it :)
Simply input any three values
Based on the given statement or reasoning above made by a student, what makes her reasoning incorrect is the part where she mentioned that "if they had not been built, she would not be exposed to radioactivity." This is definitely false. What makes this incorrect is that background radiation is a kind of radiation that is emitted by the sun, stars, and other bodies outside the universe and therefore, no one can escape from this. Hope this helps.
Answer:
Energy needed = 54.02 J
Explanation:
the Energy in an elastic spring from hookes law is given as
F= ke , therefore the energy (E) is
E = 
K = 19.5 N/cm
e = 1.39cm
E =
x 19.5 x 1.39
E = 13.55 J
The energy to stretch the spring for 6.93cm is
E =
x 19.5 x 6.93
E = 67.57 J
The more energy needed for the further stretch is
67.57 - 13.55
Energy needed = 54.02 J