physics

need help on this three part one
its about inelastic collisions momentum and energy related with work

Find the speed at which Superman (mass=76.0 kg) must fly into a train (mass = 17620 kg) traveling at 60.0 km/hr to stop it.

Running into the train at that speed would severely damage both train and passengers. Calculate the minimum time Superman must take to stop the train, if the passengers experience an average horizontal force of 0.430 their own weight.

How far does the train then travel while being slowed to a stop?

  1. 👍
  2. 👎
  3. 👁
  1. first, use conservation of momentum to find superman must fly.

    Second, use impulse=change of momentum
    You are given the average force.

    averageforce*time=weight/g *velocity
    .43avgweight*tim=avgweigh/g *velocity
    solve for time

    Lastly, the average velocity stopping is 30km/hr, you know the time, so solve for distance.

    1. 👍
    2. 👎
    👤
    bobpursley
  2. first part:
    Pi=Pf
    Pf=0 (train is not moving)
    0= m1v1 + m2v2
    v2=m1v1/m2

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics Thanks

    Please help... Let g be the acceleration due to gravity at the surface of a planet of radius R. Which of the following is a dimensionally correct formula for the minimum kinetic energy K that a projectile of mass m must have at

  2. Physics

    A hydrogen atom is in its third excited state (n=4). Using Bohr theory of the atom calculate (a) the radius of the orbit, (b) the linear momentum of the electron, (c) the angular momentum of the electron (d) the kinetic energy (e)

  3. Chemistry

    Which of the following is a correct statement about collision theory? A. All collisions lead to chemical reactions. B. Most collisions lead to chemical reactions. C. Very few reactions involve particle collisions. D. Effective

  4. Chemistry

    1. Calculate the delta H for H2(g)+O2(g)=H2O2(g) Bond energies, kJ x mol^-1 H-H 432 H-O 459 O-O 207 O=O 494 I did: deltaH=(2(207kJ/mol))-(432kJ/mol+494kJ/mol) =-512kJ is that correct? 2. The theoretical effect of an increase in T

  1. physics

    the speed of the fastest pitched baseball was 45 m/s, and the ball's mass was 145 g. (a) What was the magnitude of the momentum of this ball, and how many joules of kinetic energy did it have? (b) How fast would a 57 gram ball

  2. physics

    Which of the following statements is true for an inelastic collision? A. Both momentum and kinetic energy are conserved. B. Momentum is conserved, but kinetic energy is not conserved. C. Kinetic energy is conserved, but momentum

  3. Chemistry

    1. According to the collision theory of chemical reactions: A. High energy collisions result in few successful reactions as there isn’t sufficient time for the products to react. B. High energy collisions lead to the successful

  4. Physics Momentum

    1) Two 1 kg balls move away from each other, one traveling 5 m/s to the right, the other 5 m/s to the left. What is the magnitude of the total momentum of the system? 2) Two 1000 kg cars drive east; the first moving at 20 m/s, the

  1. PHYSICS - PLEASE HELP

    Part A: A cardinal (Richmondena cardinalis) of mass 4.50×10^−2 kg and a baseball of mass 0.142 kg have the same kinetic energy. What is the ratio of the cardinal's magnitude p(c) of momentum to the magnitude p(b) of the

  2. Chemistry

    Given N2(g) + 3H2 = 2NH3(g), which scenario will allow you to eventually reach an equillibrium mixture involving these chemicals? A. Place only H2 into a sealed vessel. B.Place only NH3 into a sealed vessel. C.Place only N2 into a

  3. Please help with Physics Quickly

    1. How are impulse and momentum related? (Points : 1) Impulse is the change in momentum of an object. Momentum is the change in impulse acting on an object. Impulse and momentum are always equal in magnitude. Impulse and momentum

  4. Science

    The inner planets- Mercury, Venus, Earth and Mars- were formed by a. Supernovas b. repeated collisions of asteroid sized debris (My Answer) ****** c. masses of cold hydrogen and helium d. collisions of large galaxies

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