Answer: 17.68 s
Explanation:
This problem is a good example of Vertical motion, where the main equation for this situation is:
(1)
Where:
is the height of the ball when it hits the ground
is the initial height of the ball
is the initial velocity of the ball
is the time when the ball strikes the ground
is the acceleration due to gravity
Having this clear, let's find
from (1):
(2)
Rewritting (2):
(3)
This is a quadratic equation (also called equation of the second degree) of the form
, which can be solved with the following formula:
(4)
Where:



Substituting the known values:
(5)
Solving (5) we find the positive result is:

We know, by conservation of energy :

Therefore,

Putting given values, we get :

Therefore, the spring be compressed to 6.93 cm to send the ball twice as high.
Hence, this is the required solution.
2e min :)) pls park braliest
The momentum of a 5kg object that has a velocity of 1.2m/s is 6.0kgm/s.
<h3> MOMENTUM:</h3>
Momentum of a substance is the product of its mass and velocity. That is;
Momentum (p) = mass (m) × velocity (v)
According to this question, an object has a mass of 5kg and velocity of 1.2m/s. The momentum is calculated thus:
Momentum = 5kg × 1.2m/s
Momentum = 6kgm/s.
Therefore, the momentum of a 5kg object that has a velocity of 1.2m/s is 6.0kgm/s.
Learn more about momentum at: brainly.com/question/250648?referrer=searchResults
D. used by the entire scientific community
B. more accurate system of measurement