1. Questions

physics

A catapult launches a test rocket vertically upward from a well, giving the rocket an initial speed of 79.0 m/s at ground level. The engines then fire, and the rocket accelerates upward at 3.90 m/s2 until it reaches an altitude of 980 m. At that point its engines fail, and the rocket goes into free fall, with an acceleration of −9.80 m/s2. (You will need to consider the motion while the engine is operating and the free-fall motion separately.)

(a) For what time interval is the rocket in motion above the ground?
[40.51 seconds]

(b) What is its maximum altitude in kilometers?
[? km]

(c) What is its velocity just before it hits the ground?
[? m/s]

  1. 👍
  2. 👎
  3. 👁
ann

  1. V^2 = Vo^2 + 2a*h
    V^2 = 79^2 + 7.8*980 = 13,885
    V = 117.83 m/s. @ 980 m

    a. V = Vo + a*t = 117.83
    79 + 3.9t = 117.83
    3.9t = 117.83-79 = 38.83
    Tr1 = 9.96 s. to rise to 980 m.

    V = Vo + g*t
    117.83 - 9.8t = 0
    9.8t = 117.83
    Tr2 = 12.02 s to reach max. ht.

    hmax = ho + (V^2-Vo^2)/2g
    hmax=980 + (0-(117.83)^2)/-19.6=1688 m.
    = max. ht

    hmax = Vo*t + 0.5g*t^2 = 1688 m
    0 + 4.9t^2 = 1688
    t^2 = 345
    Tf = 18.57 s. = Fall time.

    T = Tr1 + Tr2 + Tf
    T = 9.96+12.02+18.57 = 40.55 Seconds.

    b. hmax = 1688 m. = 1.688 km. See previous calculation.

    c. V^2 = Vo^2 + 2g*hmax
    V^2 = 0 + 19.6*1688 = 33,084.8
    V = 182 m/s.

    1. 👍
    2. 👎
    Henry

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics

    A 15.0-kg test rocket is fired vertically from Cape Canaveral. Its fuel gives it a kinetic energy of 1961 J by the time the rocket motor burns all the fuel. What additional height will the rocket rise? m - how do you organize

  2. Calculus

    If a rocket is shot vertically upward from the ground with an initial velocity of 192 ft/sec. a. When does it reach its maximum height above the ground? b. What is the maximum height reached by the rocket? c. How long does it take

  3. physics

    A small weather rocket weighs 14.7 N. The rocket is carried up by a balloon. The rocket is released from the balloon and fired, and its engine exerts an upward force of 10.2 N on the rocket. What is the acceleration of the rocket?

  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. Physics

    A model rocket has a mass of 0.435 kg. It is mounted vertically and launches directly up with a thrust force of 13.1 N. a) What is the weight of the rocket? b) Determine the net force on the rocket as it is launched. c) What is

  2. science

    A rocket is shot upward from the ground with an initial velocity of 15.5 m/s. How high does the rocket travel?

  3. math

    a model rocket is projected straight upward from the ground level. It is fired with an initial velocity of 192 ft/s. How high is the rocket after 10 seconds? When is the rocket at a height of 432 feet? What is the maximum height

  4. physics

    A test rocket is fired straight up from rest. The net acceleration is 20 m/s2 upward and continues for 4.0 seconds, at which time the rocket engines cease firing. What maximum elevation does the rocket reach?

  1. physics

    The engine of a toy rocket supplies an average acceleration of 38.0 m/s/s to the rocket for an interval of 0.80 s. A.)If the toy roocket is launched vertically, how high does it rise in this interval? B.) How fast is the rocket

  2. 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.

  3. 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

  4. physics

    When it is 152 m above the ground, a rocket traveling vertically upward at a constant 9.50 m/s relative to the ground launches a secondary rocket at a speed of 12.4 m/s at an angle of 50.0 degrees above the horizontal, both

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