A $1500 - \mathrm { kg }$ Car Traveling At $90 \mathrm {~km} / \mathrm { h }$

Multiple Choice

A $1500 - \mathrm { kg }$ car traveling at $90 \mathrm {~km} / \mathrm { h }$ toward the east suddenly collides with a $3000 - \mathrm { kg }$ car traveling at $60 \mathrm {~km} / \mathrm { h }$ toward the south. The two cars stick together after the collision. What is the speed of the cars after collision?

A) 14 m/s
B) 17 m/s
C) 22 m/s
D) 8.3 m/s