At first glance, the image above looks simple — three tanker trucks labeled 1, 2, and 3, all moving forward. But there’s a hidden detail that turns this into a clever physics puzzle.
The question is: Which truck is braking?
To find the correct answer, you don’t need advanced knowledge — just careful observation and a bit of common sense about how liquids behave when a vehicle moves.
🚛 Truck 1
In the first truck, the liquid inside the tank is tilted toward the back.
This indicates that the liquid is being pushed backward. When this happens, it usually means the truck is accelerating forward, not braking. The force pushes the liquid opposite to the direction of acceleration.
So, Truck 1 is not braking — it’s likely speeding up.
🚛 Truck 2
In the second truck, the liquid is tilted toward the front of the tank.
This is a key detail. When a vehicle brakes, everything inside it continues moving forward due to inertia. As a result, the liquid shifts toward the front.
This is exactly what we see here — the liquid is pushed forward, clearly indicating that this truck is slowing down or braking.
🚛 Truck 3
In the third truck, the liquid appears level and evenly distributed.
This suggests that there is no strong forward or backward force acting on it. In other words, the truck is likely moving at a constant speed without accelerating or braking.
✅ Final Answer
Based on how liquids react to motion and force:
👉 Truck 2 is the one that is braking.