+0  
 
0
124
3
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please check my answer on this

 May 4, 2020
 #1
avatar+111430 
+1

x  =  t + 3     ⇒   t  = x - 3

y = 2t^2  - 4

 

 

y = 2 ( x - 3)^2  - 4

 

y = 2 (x^2 -6x + 9) - 4

 

y = 2x^2 - 12x  + 14     correct  !!!!

 

When

t =  -4,   x  =  -1

t = 0 ,    x  =   3

 

GOOD JOB  !!!!!

 

 

cool cool cool

 May 4, 2020
 #2
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0

Thank you! could you possibly look at another post I made earlier that says

 

Sam attempts a 42-yard field goal in a football game. For his attempt to be a success, the football needs to pass through the uprights and over the crossbar that is 10 feet above the ground.

Sam kicks the ball from the ground with an initial velocity of 70 feet per second, at an angle of 50° with the horizontal.

Which statement is true of Sam's attempt?

The kick is good! The football clears the crossbar by approximately 6 feet.

The kick is good! The ball clears the crossbar by nearly 2 feet.

The kick is good! The ball clears the crossbar by nearly 15 feet.

The kick is not successful. The ball hits the ground short of the crossbar.

Guest May 4, 2020
 #3
avatar+111430 
+1

We can use this equation

 

y  = -16t^2  + V0sin (A) *t   + H0

 

Where  V0  =  initial velocity

H0  =  initial height  = 0

A  = the launch angle

t  = time

42 yds  = 126 ft

 

The time it takes for  the kick to reach the  crossbar can be found as     

 

126  =  70cos(70°) * t

 

t  =  126 / [70 cos (50°)]  = 2,8 s

 

So

 

To find  the  height  at the end we have

 

y = -16 (2.8)^2 + (70)sin (50°)*(2.8)

 

y =  24.87 ft

 

It clears the bar by 14.87 ft  ≈  15 ft

 

 

cool cool cool

 May 4, 2020

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