Answer:
1) 58 m
2) t = 2 s
3) 78 m
4) t = 6 s
5) It changes the y-intercept (58) to zero
6) [tex]h(t)=-4.9t^2+19.8t[/tex]
7) h = 20 m
t = 4 s
Step-by-step explanation:
[tex]h(t)=-4.9t^2+19.8t+58[/tex]
1) When t = 0:
[tex]\implies h(0)=-4.9(0^2)+19.8(0)+58=58[/tex]
Therefore, the height of the cannon before it is launched is 58 m
2) To find the time when the parabola reaches its max height, differentiate the function with respect to t, equal to zero, then solve for t:
[tex]\implies h'(t)=-9.8t+19.8[/tex]
[tex]\implies h'(t)=0 \\\\\implies-9.8t+19.8=0\\\\\implies t=2.020408163...\\\\\implies t=2 \ \textsf{s (nearest whole number)}[/tex]
3) The maximum height of the cannonball is when t = 2.020408163...:
[tex]\implies h(2.020408163...)=-4.9(2.020408163...^2)+19.8(2.020408163...)+58=78.0020408...[/tex]
Therefore, the maximum height of the cannonball is 78 m (nearest whole number)
4) Set the function to zero and solve for t:
[tex]\implies-4.9t^2+19.8t+58=0\\\\\implies t=-1.96942..., t=6.01024...[/tex]
As time is positive, t = 6 s (nearest whole number)
5) If you launch the cannonball from the ground, where [tex]h_i=0[/tex], then the y-intercept will be 0 and the function will be [tex]h(t)=-4.9t^2+19.8t[/tex]
6) [tex]h(t)=-4.9t^2+19.8t[/tex]
7) To find the maximum height of the parabola, differentiate the function with respect to t, equal to zero, solve for t, then substitute the found value for t into the equation:
[tex]\implies h(t)=-9.8t+19.8[/tex]
[tex]\implies h'(t)=0 \\\\\implies-9.8t+19.8=0\\\\\implies t=2.020408163...\\\\\implies t=2 \ \textsf{s (nearest whole number)}[/tex]
[tex]\implies h(2.020408163...)=-4.9(2.020408163...)^2+19.8(2.020408163...)=20.00204081...[/tex][tex]\implies h = 20 \textsf{ m (nearest whole number)}[/tex]
To find the time it took to hit the ground, set the function to zero and solve for t:
[tex]\implies -4.9t^2+19.8t=0\\\\\implies t=0, t=4.04081632653...[/tex]
[tex]\implies t=4 \textsf{ s (nearest whole number)}[/tex]