Tuesday

September 16, 2014

September 16, 2014

Posted by **bill** on Thursday, December 18, 2008 at 5:41pm.

Two identical cars hit each other and lock bumpers. In each of the following cases, what are the speeds of the cars immediately after coupling bumpers? (a) A car moving with a speed of 90 km/h approaches a stationary car; (b) two cars approach each other with speeds of 90 km/h and 120 km/h, respectively; (c) two cars travel in the same direction with speeds of 90 km/h and 120 km/h, respectively.

- physics -
**Damon**, Thursday, December 18, 2008 at 5:54pmThese are all conservation of momentum problems, but easy because the cars stick together after the crash so the final mass is (2m)and they are both at the same final speed v

so

m u1 + m u2 = 2m v

or

u1 + u2 = 2v for all cases

for example for part b

u1 = 90

u2 = -120

so for part b

90 - 120 = 2 v

v = -15 answer for part b

You should be able to do parts a and c now.

**Answer this Question**

**Related Questions**

physics - Two identical cars hit each other and lock bumpers. If a car moving ...

physics - Hi, i really need help with this question. Two identical cars hit each...

Physics - Two equal mass cars collide head to tail and their bumpers lock. One ...

physics - two equal mass cars collide head to tail and their bumpers lock. One ...

physics - two equal mass cars collide head to tail and their bumpers lock. One ...

college physics - Two cars of equal mass are traveling as shown in the figure ...

college physics - Two cars of equal mass are traveling as shown in the figure ...

physics - Please decide which of the following statements for car collisions are...

Physics - Two cars crash into each other at an intersection on a very icy road. ...

Physics - Two cars crash into each other at an intersection on a very icy road. ...