Questions

How many reckless drivers can you spot in this video?

And what was the force that caused the tissue box to jump forward then backward?

Answer

Three.

The first reckless driver was the one that stopped the car in the middle of the highway (probably to insert the cashcard into the in-vehicle unit before passing under the ERP gantry).

The second reckless driver was the one that swerved abruptly into the right lane (to avoid stopping behind the first car).

The third reckless driver was the one that failed to brake in time and crashed into the back of this car.

Now regarding the tissue box and the mysterious force.

Jumped forward

Well the tissue box did not jump forward. It only appeared to jump forward because it did not slow down as fast as the car. When the driver jammed his brakes, the car was able to decelerate quickly because of the friction between the road surface and the tyre (asphalt-rubber). The tissue box, however, was not able to decelerate as quickly because the friction between the dashboard and the tissue box (plastic-paper) was too weak. There was no mysterious force causing the tissue box to jump forward. It was merely its inertia demanding that it continues moving forward.

Jumped backward

Again the tissue box did not jump backward. It only appeared to jump backward because it remained at rest while the car lunged forward (because the car has just been rear-ended by the car behind). There was no mysterious force causing the tissue box to jump backward. It was merely its inertia demanding that it remains at rest.

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