With The Amazing SpiderMan being filmed in the city of Rochester, I'm sure a lot of people are curious: how does he do it?! How strong does spidermans web need to be? How much force does it need for Spiderman to be a successful superhero? Is it likely that if we were about to fall off a cliff Spiderman could catch us with his web and save us just in time? What about if we were about to drive off a cliff in a car? What about a train? Spiderman has to have some pretty amazing talents to be able to save the day, but we don't know if its actually realistic. It would sure be nice to know that if my Honda Odysey "Oliver" was falling off a cliff that Spiderman would be able to save me before I flew off the cliff and right into a lake, sinking to the bottom to my doom. The question we're going to answer is how much force spiderman would need to be able to save my car. Lets have a look.
Approximately Olivers mass is 2730 kilograms, and I was late to work that day so suppose Oliver is speeding a little and I'm traveling down the road at 20 meters per second when all of a sudden a cliff appears out of nowhere and I'm about to plummet to my death. The distance from my van to the cliff is 50 meters. And we know the acceleration on earth due to gravity is 9.81 meters/second squared. How long would it take before I fell off the cliff? Well lets see:
Velocity initial = 20 m/s
Velocity final = ?
Acceleration = 9.81 m/s(2)
Distance = 50 m
Time = ?
Mass = 2730 kg
To figure out how long it would take me to fall of the cliff we could use the equation V= D/T. So the velocity, (20 m/s) is equal to the Distance (50 m) over the time. To figure out the time the equation can be rearranged to T = D/V. After plugging everything in, (50 m)/ (20 m/s) is equal to 2.5 seconds. Spiderman only has 2.5 seconds to save me before my van takes the leap of faith. To figure out how much force Oliver is exerting moving towards the clif, you would use the equation, Force = Mass x Acceleration. So the Force Oliver is exerting would be 262724 Newtons. For Spiderman to exert the same or a greater force, or for him to stop my car or pull it away from the cliff, he would need to be accelerating the opposite way to have a greater Force since his mass if much less than Oliver. Lets assume Spiderman is around 72.0 kg, (he's not one of the bulkier superheros). And his Force needs to be equal to 262724 Newtons.
F = MA > (262724 Newtons) = (72.0 kg)(A) > (262724 N) / (72.0 kg) = A >
Spiderman would need to be accelerating the opposite direction at 3648.9 meters/second squared.
Hmmmm now thats pretty fast. Us mere humans would probably never be able to pull a stunt like this but I'm sure
Spiderman could. Just incase you're ever driving down the street with the same speed as Oliver in a car of a similar weight, just keep in mind when Spiderman comes down to save you, that he's working pretty hard.