Answer:
Stretch can be obtained using the Elastic potential energy formula.
The expression to find the stretch (x) is 
Explanation:
Given:
Elastic potential energy (EPE) of the spring mass system and the spring constant (k) are given.
To find: Elongation in the spring (x).
We can find the elongation or stretch of the spring using the formula for Elastic Potential Energy (EPE).
The formula to find EPE is given as:

Rewriting the above expression in terms of 'x', we get:

Example:
If EPE = 100 J and spring constant, k = 2 N/m.
Elongation or stretch is given as:

Therefore, the stretch in the spring is 10 m.
So, stretch in the spring can be calculated using the formula for Elastic Potential Energy.
Answer:
B. Attract each other with a force of 10 newtons.
Explanation:
Statement is incorrectly written. <em>The correct form is: A </em>
<em> charge and a </em>
<em> at a distance of 0.3 meters. </em>
The two particles have charges opposite to each other, so they attract each other due to electrostatic force, described by Coulomb's Law, whose formula is described below:
(1)
Where:
- Electrostatic force, in newtons.
- Electrostatic constant, in newton-square meters per square coulomb.
- Magnitudes of electric charges, in coulombs.
- Distance between charges, in meters.
If we know that
,
and
, then the magnitude of the electrostatic force is:


In consequence, correct answer is B.
I assume that the ball is stationary (v=0) at point B, so its total energy is just potential energy, and it is equal to 7.35 J.
At point A, all this energy has converted into kinetic energy, which is:

And since K=7.35 J, we can find the velocity, v:
Answer:
Explanation:
a = (vf - vi) / t
a = (50 - 90) / 10.0
a = -4 km/h/s(1000 m/km / 3600 s/h)
a = - 1.11 m/s²
Answer:
24cm/s
Explanation:
A=L*w
A'=L'*w'
L=13
w=5
L'=4
w'=6
A=?
A'=?
A=L*w
A=13*5
A=65
A'=L'*w'
A'=4*6
A'=24
*the given lengths are just to throw you off*