Physics of Deadpool jumping off bridge

I was watching the trailer for the upcoming movie “Deadpool” with Ryan Reynolds, when one scene caught my eye. In the scene, the lead character jumps from a bridge, breaks through a sunroof of a passing vehicle, and lands perfectly in the back seat. I started thinking, is that even physically possible? what kind of speeds would be required?

The numbers

According to the Marvel directory, Deadpool is 6’2″ (1.9m) tall. A standard sunroof is 30″x15″, but we can see from the trailer that this sunroof is larger than standard.

If we look at this sunroof from a couple angles, this sunroof is approximately square. In the lower shot, the 4 sides of the big sunroof are each approximately 37 pixels, and the second, smaller sunroof is in the front is 38pixels to 19pixels, which is approximately the same ratio as a standard sunroof.

With no absolute measurements possible, we’ll have to assume that the front sunroof is standard sized, which makes the big sunroof approximately twice as long, or 30″x30″ (0.76m x 0.76m). This approximation is a weak point in the calculation, but you’ll see from the numbers that even a moderest size discrepancy doesn’t make much of a difference.

The problem

To summarize the problem, the entire 6’2″ (1.9m) of a human body must pass through 30″ (0.76m) of a moving sunroof, or else his body gets clipped by the roof of the car.

The trivial solution, of course, is when the car’s is not moving, so he just has to hit a stationary target. However, that makes for a boring chase scene.

For simple calculations, we’ll discount the width of the human body, and just assume that he is paper thin and that he hits exactly at the front of the sunroof (rather than the middle). Alternatively, we could subtract an additional 6″ from the available sunroof space to accomodate for the space of the body in the sunroof space, but this way keeps the numbers easy (and the calculations generous). Thus, for his magic paper thin 6’2″ to pass entirely through 30″ of open space, his downward velocity needs to be at least 2.5x that of the car’s forward velcoity (1.9m:0.76m).

The bad guys are on the freeway, so hopefully they’re moving at at least freeway speeds, 60 to 80mph. If they’re going 80 mph, that means Deadpool will need to be going 200mph when he reaches the car. While most people cite the terminal velocity of a human as about 124mph, skydivers with the right equipment and body position regularly hit 200mph. According to Newtonian equations, for Deadpool to reach an instantaneous velocity of 200mph (89 m/s), he’ll need to have fallen for 10 seconds (first equation) from a height of 490m (second equation)

We can see from the initial scene that he is on a freeway overpass not a skyscaper, and is honestly more like 50 or 60 feet in the air. For the sake of being generous, we’ll give him a jump height of 30m. From the above equations, he’ll have 2.5s of freefall, and will reach a max instantaneous velocity of 24m/s (54mph); therefore the villians are having a leisurely Sunday drive at about 20mph.

Even if we give him 60m of height, the numbers still work out to 3.5s of freefall, a max velocity of 34m/s (75mph), which means our villians are topping out at 30mph. If we take away the generous approximations- the paper thin body, him hitting at the absolute front edge- then he loses at least half or even more of the working space, raising the required ratio of his speed to that of the car to greater than 5:1, putting our villians at a max speed of 15mph.

In conclusion

Jumping through the sunroof of a moving car is a lot harder than it looks.