Converting Initial Velocity to SI Units

Oct 13, 2025 by wbrum.org 26 views

Introduction

When a car collides with an object, such as a tree, the force exerted on the vehicle can be significant. In this scenario, we are given the mass of the car, its initial velocity, and the time period over which the collision occurs. Our goal is to determine the magnitude of the force exerted on the car during the collision.

Given Information

Mass of the car: $m = 1200 \, \text{kg}$
Initial velocity of the car: $60.0 \, \text{mph}$
Time period of the collision: $0.0500 \, \text{seconds}$

Converting Initial Velocity to SI Units

To perform calculations, we need to convert the initial velocity from miles per hour (mph) to meters per second (m/s). We can use the following conversion factor:

1 mph = 0.44704 m/s

Using this conversion factor, we can calculate the initial velocity in m/s:

v_i = 60.0 \, \text{mph} \times \frac{0.44704 \, \text{m/s}}{1 \, \text{mph}} = 26.83 \, \text{m/s}

Calculating the Change in Velocity

During the collision, the car comes to rest, so the final velocity is zero. We can calculate the change in velocity using the following equation:

\Delta v = v_f - v_i = 0 - 26.83 \, \text{m/s} = -26.83 \, \text{m/s}

Calculating the Acceleration

We can calculate the acceleration using the following equation:

a = \frac{\Delta v}{\Delta t} = \frac{-26.83 \, \text{m/s}}{0.0500 \, \text{s}} = -537.6 \, \text{m/s}^2

Calculating the Force Exerted on the Car

We can calculate the force exerted on the car using Newton's second law of motion:

F = ma = 1200 \, \text{kg} \times -537.6 \, \text{m/s}^2 = -643,520 \, \text{N}

Magnitude of the Force

The magnitude of the force exerted on the car is the absolute value of the force:

|F| = |-643,520 \, \text{N}| = 643,520 \, \text{N}

Conclusion

In this scenario, we calculated the magnitude of the force exerted on a car during a collision with a tree. We used the given information, including the mass of the car, its initial velocity, and the time period of the collision, to determine the force exerted on the vehicle. The result shows that the force exerted on the car is significant, with a magnitude of 643,520 N.

Discussion

The force exerted on the car during a collision can be significant, and it is essential to consider the safety implications of such an event. In this scenario, the force exerted on the car is due to the deceleration of the vehicle, which occurs over a short time period. The magnitude of the force is directly proportional to the mass of the car and the deceleration, and it is inversely proportional to the time period of the collision.

Limitations

One limitation of this calculation is that it assumes a perfectly inelastic collision, where the car comes to rest immediately after the collision. In reality, the collision may be partially elastic, and the car may not come to rest immediately. Additionally, the calculation assumes that the force exerted on the car is constant over the time period of the collision, which may not be the case in reality.

Future Work

Future work could involve considering the effects of the collision on the occupants of the car, including the forces exerted on them and the potential for injury. Additionally, the calculation could be modified to account for the possibility of a partially elastic collision, where the car does not come to rest immediately.

References

[1] Halliday, D., Resnick, R., & Walker, J. (2013). Fundamentals of physics (10th ed.). John Wiley & Sons.
[2] Serway, R. A., & Jewett, J. W. (2018). Physics for scientists and engineers (10th ed.). Cengage Learning.

Note: The references provided are for general information purposes only and are not specific to this calculation.

Introduction

In our previous article, we calculated the magnitude of the force exerted on a car during a collision with a tree. In this article, we will answer some frequently asked questions related to this topic.

Q: What is the most significant factor that affects the force exerted on a car during a collision?

A: The most significant factor that affects the force exerted on a car during a collision is the deceleration of the vehicle. The deceleration is directly proportional to the force exerted on the car.

Q: How does the mass of the car affect the force exerted on it during a collision?

A: The mass of the car affects the force exerted on it during a collision. The more massive the car, the greater the force exerted on it during a collision.

Q: What is the difference between a perfectly inelastic collision and a partially elastic collision?

A: A perfectly inelastic collision is a collision where the objects stick together after the collision, and the final velocity is the same as the velocity of the combined objects. A partially elastic collision is a collision where the objects do not stick together after the collision, and the final velocity is different from the velocity of the combined objects.

Q: How does the time period of the collision affect the force exerted on the car?

A: The time period of the collision affects the force exerted on the car. The shorter the time period of the collision, the greater the force exerted on the car.

Q: Can the force exerted on a car during a collision be reduced?

A: Yes, the force exerted on a car during a collision can be reduced. This can be achieved by reducing the deceleration of the vehicle, which can be done by using airbags, seatbelts, and other safety features.

Q: What is the role of airbags in reducing the force exerted on a car during a collision?

A: Airbags play a crucial role in reducing the force exerted on a car during a collision. They help to distribute the force of the collision over a longer period, reducing the deceleration of the vehicle and the force exerted on the occupants.

Q: Can the force exerted on a car during a collision be predicted?

A: Yes, the force exerted on a car during a collision can be predicted using mathematical models and simulations. These models take into account the mass of the car, the initial velocity, the time period of the collision, and other factors to predict the force exerted on the car.

Q: What are the limitations of calculating the force exerted on a car during a collision?

A: The limitations of calculating the force exerted on a car during a collision include the assumption of a perfectly inelastic collision, the assumption of a constant force exerted on the car, and the lack of consideration for other factors such as the angle of impact and the type of collision.

Q: What are the implications of the force exerted on a car during a collision on the occupants?

A: The force exerted on a car during a collision can have significant implications on the occupants. The force can cause injury or even death, depending on the severity of the collision and the safety features of the vehicle.

Conclusion

In this article, we have answered some frequently asked questions related to the force exerted on a car during a collision. We have discussed the factors that affect the force exerted on the car, the role of airbags in reducing the force, and the limitations of calculating the force. We have also discussed the implications of the force exerted on the occupants.

References

[1] Halliday, D., Resnick, R., & Walker, J. (2013). Fundamentals of physics (10th ed.). John Wiley & Sons.
[2] Serway, R. A., & Jewett, J. W. (2018). Physics for scientists and engineers (10th ed.). Cengage Learning.

Note: The references provided are for general information purposes only and are not specific to this article.