The toy rocket hits the ground when h(t) = 0.
So, h(t) = 0 = -9t^2 + 81.
Solving the equation,
-9t^2 = -81
Dividing by -9
t^2 = 9
Taking the square root.
t = 3
The answer is 3 seconds.
A. the answer is 6x^2+9x-42
Total cost for tiles and paints is $924.
Step-by-step explanation:
We have been given that a community hall is in the shape of a cuboid. The hall is 40m long 15m high and 3m wide.
The paint will be required for 4 walls and ceiling.
Let us find area of walls and ceiling.
Therefore, the area of walls and ceiling is 1410 square meters.
Given: Cost for 10 litre of paint is $10 and 10 litre paint covers 25 square meter. Therefore,
Therefore, the total painting cost is $564.
Tiles will be required for floor. Let us find the area of floor.
Given: 1m squared floor tiles costs $3. So,
Therefore, the total cost for tiles is $360.
Now let us find combined total cost of tiles and paint.
Therefore, the combined total cost of tiles and paint is $924.
