Answer:
The velocity of the skateboard is 0.774 m/s.
Explanation:
Given that,
The spring constant of the spring, k = 3086 N/m
The spring is stretched 18 cm or 0.18 m
Mass of the student, m = 100 kg
Potential energy of the spring, 
To find,
The velocity of the car.
Solution,
It is a case of conservation of energy. The total energy of the system remains conserved. So,
v = 0.774 m/s
So, the velocity of the skateboard is 0.774 m/s.
The popular GPS devices that people use to find directions while driving use "Global Navigation Satellite System (GNSS)".
<u>Explanation:</u>
The umbrella term for all global satellite tracking systems is GNSS i.e Global Satellite Navigation System. This involves satellite constellations circulating over the surface of the earth and continuous signal transmission that allow users to evaluate their location.
A satellite array of 18–30 medium Earth Orbit (MEO) satellites distributed across several orbital planes typically achieves greater coverage for each network. The specific systems differ, but use > 50 ° orbital inclinations and approximately twelve hours orbital cycles.
In this question, you're determining the time (t) taken for an object to fall from a distance (d).
The equation to represent this is:
Time equals the square root of 2 times the distance divided by the gravitational force of earth.
In equation from it looks like this (there isn't an icon to represent square root so just pretend like there's a square root there):
t = 2d/g (square-rooted)
d = 8,848m and g = 9.8m/s
Now plug in the information we have:
t = 2 x 8,848m/9.8m/s (square-rooted)
The first step is to multiply 2 times 8,848m:
t = 17,696m/9.8m/s (square-rooted)
Now divide 9.8m/s by 17,696m (note that the two m's (meters) cancels out leaving you with only s (seconds):
t = 1805.72s (square-rooted)
Now for the last step, find the square root of the remaining number:
t = 42.5s
So the time it takes the ball to drop from the height (distance) of 8,848 meters, and falling with the gravitational pull of 9.8 meters per second is 42.5 seconds.
I hope this helps :)
