A car of mass `m` moving over a concave bridge of radius `r` .Find the normal reaction acting on car when it is at lowest point the bridge

Explanation

To find the normal reaction acting on a car of mass \( m \) when it is at the lowest point of a concave bridge of radius \( r \), we can follow these steps:

### Step 1: Identify the forces acting on the car
At the lowest point of the concave bridge, two main forces are acting on the car:
- The gravitational force (\( mg \)) acting downwards.
- The normal reaction force (\( N \)) acting upwards from the surface of the bridge.

### Step 2: Apply Newton's second law
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