Math

A toy rocket is launched with an initial velocity of 180 m/s. The height of the rocket, in metres, can be modelled by h = –5t2 + 180t, where t is the time in seconds the rocket is in the air. How long will the rocket stay above a height of 1000 m
Answer: 22.3 s
The answer says to first put in vertex form by
h = –5t2 + 180t
h=–5(t2 –36t+324–324)
h =–5(t – 18)2 + 1620

But why is it +324. And not +(36/2)^2

  1. 👍
  2. 👎
  3. 👁
  4. ℹ️
  5. 🚩
  1. 324 = +(36/2)^2

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
    👤
    Ms. Sue

Respond to this Question

First Name

Your Response

Similar Questions

  1. pre ap math

    a toy rocket is launched from a platform that is 48 feet high. the rockets height above the ground is modeled by h=-16t^2+32t+43. find the maximum height of the rocket find the time it will take for the rocket to reach the ground.

  2. Algebra

    A toy rocket that is shot in the air with an upward velocity of 48 feet per second can be modeled by the function f(t)=-16t^2+48t , where t is the time in seconds since the rocket was shot and f(t) is the rocket’s height. What

  3. Math

    A rocket is launched from the top of a 50 foot cliff with an initial velocity of 120 feet per second. The height, h, of the rocket after t seconds is given by the equation h=-16t^2 + 120t+ 50. How long after the rocket is launched

  4. math

    A toy rocket is launched straight up into the air with an initial velocity of 60 ft/s from a table 3 ft above the ground. If acceleration due to gravity is –16 ft/s2, approximately how many seconds after the launch will the toy

  1. Math

    A model rocket is launched with an initial velocity of 164ft/sec. It's height h, in feet, after t seconds is given by the formula h=164t-16t^2. After how many seconds will the rocket first reach a height of 400ft?

  2. Physics

    A model rocket is launched straight upward with an initial speed of 50 m/s. It accelerates with a constant upward acceleration of 2.00 m/s^2 until its engines stop at an altitude of 150 m. a) What is the max. height reached by the

  3. algebra

    A toy rocket is launched into the air at an initial velocity of 32 ft/sec, as shown on the graph below. The function s(t)=-16t^2+32t+128 gives the height of the rocket (in feet) at time t (seconds). When does the rocket hit the

  4. Mathematics

    A toy rocket is launched from a 3m platform, at 8.1 m/s. The height of the rocket is modelled by the equation h= -4.9t^2 + 8.1t + 3, where h is the height, in metres, above the ground and t is the time, in seconds. 1. After how

  1. math

    A rocket is fired into the air with an initial velocity of 98 m/s. The height ( h ) of the rocket after t seconds is given by the expression h = 98t - 4.9t2. a. What the average rate of change over the first 2 seconds. b. At what

  2. Math, Quadratic equaitons

    A toy rocket is launched form a 3m platform, at 8.2m/s. The height of the rocket is modelled by the equation h=-4.0t^2+8.1t+3 where h is the height, in metres, above the ground and t is the time, in seconds. After how many seconds

  3. AlgebraB-2

    1. What is the value of n so that the expression x² + 12x + n is a perfect square trinomial? (1 point)6 36 72 144 2. What are the solutions of the equation x2 + 4x = 96? (1 point) 2, –48 –12, 8 –2, 48 12, –8 3. What are

  4. algebra

    A rocket is launched from atop a 76-foot cliff with an initial velocity of 107 ft/s. The height of the rocket above the ground at time t is given by . A) When will the rocket hit the ground after it is launched? Round to the

View more similar questions or ask a new question.