Missing question: "What is the spring's constant?"
Solution:
The object of mass m=6.89 kg exerts a force on the spring equal to its weight:

When the object is attached to the spring, the displacement of the spring with respect to its equilibrium position is

And by using Hook's law, we can find the constant of the spring:
Answer:
(B) The speed is larger at A than at B.
Explanation:
Point B, the final point of the trajectory, has higher electric potential than point A, the initial point of the trajectory, so the electric potential energy of the charged particle increases, which means that its kinetic energy must be decreasing, thus the speed at B must be lower than the speed at A.
Answer:
4800N
Explanation:
Lets assume,
Mass of first object = m₁
Mass of second object = m₂
Distance between the two objects = r
Thus the force between the two objects will be

where, G = Universal gravitational constant
Given, F = 2400N
New mass of second object = 2m₂
Now, the force will be




Thus, F₂ = 4800N
<span>Standard deviation is a calculation. It I used in statistical analysis of a easier job. hoped this helps u </span>