4. A 2000 kg SUV traveling at 7 m/s south runs into the rear end of an 800 kg compact car sitting at a stop light in an elastic collision. If the compact car is
going forward at 7 m/s right after the collision, how fast is the SUV traveling?
5. Beaker and Honeydew are driving bumper cars. They spot each other across the
rink and head straight for each other at full speed. Honeydew and his car (130 kg
I
total) head east at 3.5 m/s while Beaker and his car (110 kg total) head west at
3.0 m/s. They have an elastic collision when they meet and Honeydew (and car)
bounces backwards at 2.4 m/s. What is Beaker's speed after the collision?