A stunt is being carried out during the making of a film - Scottish Highers Physics - Question 4 - 2018

Introduction

Car stunts involving moving vehicles present multiple challenges that can significantly affect safety and success. Understanding the physics concepts involved is crucial in analyzing these challenges.

Relative Velocity

One of the primary challenges is the relative velocity between the car and the second lorry on which it intends to land. If both vehicles are moving, the stunt driver must precisely calculate the speed of the car as well as the speed of the second lorry. The equations of motion and the relative motion of both vehicles are important here:

1. Relative Speed Calculation: If the first lorry is moving at speed $v_1$ and the second lorry at speed $v_2$, the effective speed of the car relative to the second lorry when it lands can be calculated as: $v_{relative} = v_{car} - v_{2}$ where $v_{car}$ is the speed of the car leaving the ramp.

2. Landing Accuracy: The driver must ensure that the landing is accurate. Even a small deviation can lead to catastrophic failure. The horizontal distance covered by the car during the jump can be modeled using projectile motion equations:

   t = \sqrt{\frac{2h}{g}}$$ where $d$ is the distance, $t$ is the time taken to fall height $h$, and $g$ is the acceleration due to gravity.

Forces During Landing

Another significant challenge is the forces acting on the car upon landing.

• Impact Force: When the car lands on the second lorry, it generates an impact force that can lead to the loss of control. Stunt drivers must consider the following force: $F = m imes a$ where $m$ is the mass of the car and $a$ is the deceleration upon impact.

Stability and Control

Lastly, stability after landing is critical. The driver must maintain control of the vehicle, which can be affected by factors such as:

• Weight Distribution: The weight distribution of the car while landing affects how it stays on the lorry.
• Motion of the Second Lorry: If the second lorry is moving, the combined motion can alter the center of mass, making it difficult for the stunt driver to balance.

Conclusion

In summary, to successfully carry out the stunt, the stunt driver must master the calculations involving relative velocities, understand the forces at play during landing, and maintain control of the car post-landing. It is essential to have a thorough understanding of the physics at work in this high-stakes scenario.