Cognitive:
This is because teens tend to excrete more hormones when they are in their adolescent ages causing them to act in a riskier behavior.
Emotions:
Because of their feeling that they want to have freedom.
Physical:
Their hormones are affecting their actions.
The sun is approximately 27,000 light years away from the center of our galaxy.
A force sets an object in motion when the force is multiplied by the time of its application.
Explanation:
By Hooke's Law,
F=kx
The only force acting here is weight, and x is the extension of the string (you need to convert this to mm) so
mg=kx
(0.15)(9.81)=k ((420-300)x10^-3)
Then just solve this equation.