Answer:
Step-by-step explanation:
h is the height of the pebble after a certain amount of time has gone by. Since we are told to find that time when the pebble is on the ground, we say that h = 0 since the height of something on the ground has no height at all. Then factor the quadratic.

Throw that into the quadratic formula or however you were taught to factor irrational quadratics (maybe completing the square?) to get that
t = 11.27869 sec and t = -10.52869 sec
Since we all know that time will never carry a negative value, we will disregard it and go with 11.27869 seconds. Not sure to where you are told to round.
Answer:
4312cm³
Step-by-step explanation:
volume of a prism = length×width×height
=22×14×14
=4312cm³
Answer: Area of square PQRS is 81cm^2 and of ABCD is 25cm^2
You know its a square. Which means all the sides are equal and same length. If you dont know what's a square then here is the definition:
Square is a plane figure with four equal sides and four right (90°) angles.
So now we know both of are squares, in case of the first square, PQRS, one side length is already given which is PQ=9cm. Now one side is 9cm which means all the sides are 9cm's (PQ=9cm, QR=9cm, RS=9cm,SP=9cm). So to find area just multiply them:
9cm * 9cm = 81cm^2
Now you found the area of the first square. So for the second square, ABCD, one side length is 5 cm so all the rest three sides are also 5 cm. Again, multiply them in order to find the area:
5cm * 5cm = 25cm^2
So square PQRS is 81cm^2 to that of square ABCD is 25cm^2
CAUTIONS: IT IS NOT THAT HARD YA KNOW
By the way, hope it helps! ^^