physics

An experimental rocket designed to land upright falls freely from a height of 2.88 102 m, starting at rest. At a height of 95.9 m, the rocket's engines start and provide constant upward acceleration until the rocket lands. What acceleration is required if the speed on touchdown is to be zero? (Neglect air resistance.)

  1. 👍
  2. 👎
  3. 👁
  1. Vf^2=Vi^2+2Anet*d where
    Anet=-9.8+a

    Now vi, figure from change of PE
    1/2 m vi^2=mg*(-288)-ma(-95.9)
    solve for vi.

    Then,
    vf^2=0=Vi^2+2*-9.8*-95.9+2a*-95.9
    solve for a

    Note Vi is negative, but when squared, postive. a should end up to be positive. Notice and think out why I put a - on the 288, on the 9.8, and on the 95.6.

    1. 👍
    2. 👎
    👤
    bobpursley
  2. What acceleration is required if the speed on touchdown is to be zero?

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    A model rocket is launched straight upward with an initial speed of 45.0 m/s. It accelerates with a constant upward acceleration of 1.50 m/s2 until its engines stop at an altitude of 160 m. A. what is the max height reached by the

  2. physic

    A sounding rocket, launched vertically upward with an initial speed of 79.0 m/s, accelerates away from the launch pad at 5.70 m/s2. The rocket exhausts its fuel, and its engine shuts down at an altitude of 1.15 km, after which it

  3. physics

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

  4. Physics

    A test rocket is launched vertically from ground level (y=0m), at time t=0.0 s. The rocket engine provides constant upward acceleration during the burn phase. At the instant of engine burnout, the rocket has risen to 97 m and

  1. Aerospace

    A rocket fires from rest with an upward acceleration of 35 m/s2 for 2 seconds. After this time, the engine shuts off and the rocket freely falls back to the earth. The maximum height is 314 and the height the engine shuts off is

  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. Physics

    A model rocket rises with constant acceleration to a height of 3.1 m, at which point its speed is 26.0 m/s. A.) How much time does it take for the rocket to reach this height? B.) What was the magnitude of the rocket's

  4. Physics

    A rocket is fired vertically with an upward acceleration of 30 m/s2. After 20 s, the engine shuts off and the rocket then continues rising (while in free-fall). The rocket eventually stops rising and then falls back to the ground.

  1. Algebra 2 h

    A model rocket is launched from the top of a building. The height (in meters) of the rocket above the ground is given by h( t) = -16t²+ 96t + 14, where t is the time (in seconds) since the rocket was launched. What is the

  2. Math

    the height of a rocket above the ground is modelled by the quadratic function h(t)=-4t^2+32t a) how long will the rocket be in the air ? how do you know? b) what is the maximum height that the rocket will reach ?

  3. physics

    You have designed a rocket to be used to sample the local atmosphere for pollution. It is fired vertically with a constant upward acceleration of 17 m/s2. After 20 s, the engine shuts off and the rocket continues rising (in

  4. Physics

    A model rocket is launched upward with an initial speed of 50 m/s. It accelerates with a net constant upward acceleration of 2.0 m/s^2 until its engines stop at an altitude of 150 m. (a) What is the maximum height reached by the

You can view more similar questions or ask a new question.