Saturday
March 28, 2015

Homework Help: @elena

Posted by john on Sunday, April 29, 2012 at 5:50pm.

thank you so much help with the problem. i have trouble solving part b of the problem you helped me with. it told me to give it as a percentage, I got 10% but it is wrong. can you please help me
Superman must stop a 190-km/h train in 180m to keep it from hitting a stalled car on the tracks.

part a)If the train's mass is 3.810^5kg , how much force must he exert (find the magnitude)?

part b)Compare to the weight of the train (give as %).

partc) How much force(in magnitude) does the train exert on Superman?



college physics - Elena, Sunday, April 29, 2012 at 5:09pm
(a) v=190 km/h =52.8 m/s,
a =v^2/2s =(52.8)^2/2180 = 7.74 m/s^2,
F = ma = 3.810^57.74 = 2.9410^6 N.
(b) Weight = mg = 3.810^59.8= 3.7610^6 N.
(c) F12 = -F21 = >
F = 2.9410^6 N.

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Math 141 - I am having trouble with this problem. perform the indicated ...
math - you have helped me so much, one more problem. Consider the following ...
math - What strategy did you use in solving this problem? 22. Suppose that you ...
algebra1 - could you walk-through the steps to solving this problem because I am...
Algebra - Once again, I have some confusing problems for math. If you know any ...
@ elena - In the figure the coefficient of static friction between mass (MA) ...
computers - I have trouble with problem solving. Can you help me please?
calculus - I am working on this problem and having some trouble. We're supposed ...
math - i was doing the mean theorem for this problem: (x+4)^2 (x-3) on [-4,3] i ...
Algebra 2 - Solving Quadratic Systems x^2+y^2=2 x^2-6y=10 I'm having trouble ...

Members