Final answer:
When a car drives off a cliff, gravity acts on the car's center of gravity creating a torque that causes the car to rotate forward. The loss of contact with the ground adds to the effect, with inertia making the rear of the car continue moving upward briefly while the front falls.
Step-by-step explanation:
When a car drives off a cliff, it undergoes a rotation forward as it falls due to the torque created by gravity acting on the car's center of gravity. Before the car goes off the cliff, it has gravitational potential energy which is converted to kinetic energy when the car is in free fall. The pivot point can be considered as the edge of the cliff, and since the car's center of mass is not typically at the base level with this pivot point, gravity will create a torque that causes the car to rotate forward.
This effect can be understood through Newton's first law, which states that an object will maintain its velocity unless acted upon by an external force. When the car is no longer in contact with the ground, the only force acting is gravity, which pulls the car towards the earth and causes it to accelerate. Since the force of gravity acts through the center of mass of the car, which is not at the same point where the car loses contact with the ground, a rotation is initiated.
In addition to gravity, inertial effects due to the car's motion come into play. As the car drives off, the rear end may continue its upward trajectory momentarily while the front begins to fall, further contributing to the rotating motion. This is similar to experiences in a jet or a car taking a sharp turn, where the inertial effects lead to the sensation of being pushed back into your seat or to the side of the car.