We can decompose this diagonal motion into horizontal and vertical directions, but we will focus on the former here. The horizontal velocity (V1) and bounces off with a horizontal velocity (V2) +1 m/s. The change of sign indicates a reversal of direction. Think of it as moving back and forth along the x-axis of a coordinate plane. Left is negative and right is positive.
your speed It remains the same, but speed (Remember, velocity has a direction.) In fact, because When the horizontal velocity is reversed, the speed increases significantly. (v2 – v1) = (1 – (–1)) = 2This creates high impact acceleration, as well as high normal and friction forces. Bouncing back and forth is the key to defeating gravity in this stunt.
So how much force would it take to perform such a bounce-wall jump? Let’s say your mass is 75 kilograms and the coefficient of friction is 0.6, which is conservative for a rubber sole.
First, the friction force (debtdebt) is gravity (MilligramsThe strength of the gravitational field on Earth (G) is 9.8 newtons per kilogram. Therefore, gravity (MXG) = 75 x 9.8 = 735 Newtons.
Remember that the friction force is the product of the normal force and the coefficient of friction (debtdebt = μNTherefore, to achieve a minimum friction force of 735 Newtons, a normal force of at least 1,225 Newtons is required (debtdebt/μ = 735/0.6 = 1,225).
Because both gravity and the normal force are pushing you, you need to add the two forces together to find the net force. Because they’re perpendicular, the vector sum is easy to calculate: 1,429 Newtons. (Remember, kids: Want to be parkour heroes? Learn linear algebra.)
That means you have to push back with an equal force (because force is the interaction of two things). 1,429 newtons is 321 pounds of force. That’s a lot of force, but not impossible. Eight times in a rowBut it’s not that easy.
How long will the turnaround take? From the normal force and mass of the person, we can calculate the horizontal acceleration. OnexBy definition, it is equal to the change in velocity per unit time (Δt), so we can use this to solve for the time interval.
Plugging in the numbers, we get a time interval of 0.12 seconds. In other words, if you hesitate, you fall. In short, if you want to pull off this amazing parkour stunt, you’ll have to be strong, fast and fearless, because if you run out of newtons along the way, the descent will be much faster than the ascent.
