A rock is thrown off a bridge into the water. The path of the rock can be modeled by the function h=-4.9t^2 +18t +15 where h=height in metres and t=time in seconds. a. When will the rock hit the water? b. For how long will the rock be above 20m? c. What is the maximum height that the rock reaches?

Isabel wanted to study how the area of a rectangle changes with the length if its width is fixed. She computed the areas of several rectangles that have the same width and different lengths. She then plotted the results and connected them with a line, as shown below. The graph shows the area (in mm) versus the length (in mm). Find the domain and the range of the function shown. Area (mm) 14 Length (mm)

The thickness of ice y in the Gladstone Glacier was 450 feet in 1990. By 2005, the thickness had shrunk to 400 feet. Let x be the elapsed number of years since 1990. Write a linear function that models this data. Then use the function to find the given value. (Simplify your answer and round to TWO decimal places, including zeros as needed. Example: 2 should be written as 2.00. Do not include commas.) Estimate the year when the Gladstone Glacier will be 350 feet thick. (Round your answer to TWO decimal places, including zeros as needed. Example: 2 should be written as 2.00. Do not include commas.)

The height of a ball being thrown off a roof can be modelled by the function: h (t) =-5t +15t +20, where h is the height in metres and t is the time in seconds. Determine when the ball hits the ground and the speed it is traveling (IROC) at that time. 目

follow the hint and write the solution clearly(step by step)

A soccer ball is kicked from the ground with an intitial upward velocity of 90 feet per second. The equation h(t)= -16t2+90t gives the height h of the ball after t seconds.  Give the domain and range of the function.

The path of a soccer ball can be modelled by the function h(d) = ‒0.1d2 + 0.5d + 0.6 where h = the height of the ball and d is the horizontal distance from the kicker, both in meters. How far from the kicker did the ball land? Answer step-by-steps.

Represent t(100) as a table of values for speed from 5 meters per second to 10 meters per second.

3. A child holds a ball 4 feet above the ground and throws it. The ball follows a parabolic path reaching a maximum height of 8 feet when the ball is 3.5 = 7/2 horizontal feet from the boy. Write a function representing the height H of the ball as a function in terms of the horizontal distance d. Equation: NO DECIMALS.

A variable star is one whose brightness alternately increases and decreases. For the variable star Delta Cephei, the time between periods of maximum brightness is 5 days. The average brightness ( or magnitude) of the star is 4 and its brightness varies by ±0.35 magnitude. Suppose the brightness of the star can be modeled by the equation y =acosbt + d. a. What is the value of b? b. Find a function that models the brightness of Delta Cephei as a function of time.