Cars and Transportation

finding.4ever asked:


A railroad car of ams m is moving at speed v when it collides with a second railroad car of mas M which is at rest. The two cars lock together instantaneously and move along the track.

What is the speeed of the cars immediatly after the collision?

How would you find it?

Candice

jumanji asked:


This was just a random thought of mine. Most cars can attain maximum speeds of 180mph, but maximum speed limits are usually 60-65 mph. If cars could me made to drive lower speeds, will the roads be safer?

Althea

lykastar asked:


In a road accident where one car has stuck to another on collision, accident investigators often measure the length of skidmark produced from where the vehicles collided. The mass of the two cars and the deceleration produced by the road are also measured. How can these figures be used to calculate the velocity of te cars before collision? I got this question as homework after having had a Physics lesson on Momentum. Any help will be very much appreciated. Thanks.
Thanks for all the responses. The question says that you are given the mass of the 2 cars, the deceleration after collision and the length of the skidmark.
Cons. of momentum means that total before = total after. So basically,
m1*v1 + m2*v2 = m3*v3.
So I have m1 m2 and m3 as well as v3 (which can be worked out using the suvat equation v-squared = u-squared + 2as.) As a class we haven’t gone into any details regarding friction and kinetic energy, and are just supposed to use the suvat equations and the law of conservation of momentum to answer this question. Please help!
What I’m supposed to work out is v1 and v2.

Arlen

matroidman asked:


I was in a low speed crash with a Prius and wonder if that type of car has a higher probability of being totaled than cars more traditionally engineered.

Tresa