SDN Members don't see this ad. (About Ads) So you are in a car going 60 mph an hour on the highway. In front of it a ways [10 m], there is a van with a ramp [at 30 degrees from the horizontal] on the back going at 55 mph in the same direction. Once the car reaches the van [slowly], does the car begin to accelerate incredibly quickly? How do you calculate the relative velocities once the car reaches/is first completely on the ramp? The relatively velocity of the car is 5 mph [60-55mph]. But once it is on the ramp, are you looking at a relative velocity of 60mph-0mph?