How hard the hit must be to destroy the object, just write the number.
Imagine a minimum collision force where the object is destroyed, and calculate the threshold with this:
[Speed x Mass x 0.025 = Threshold]
Example 1: Object will be destroyed when a 1.5-ton-vehicle hits it at 100 mph. What is the threshold?
Speed = 100 (mph, or whatever the Carmageddon velocity units are)
Mass = 1.5 (tons)
Threshold = ?
Speed x Mass x 0.025 = Threshold
-> 100 x 1.5 x 0.025 = 3.75
Answer: The threshold is 3.75.
Example 2: How fast must a 5-ton vehicle drive, to destroy a object which threshold is 1000?
Threshold = 1000
Mass = 5 (tons)
Speed = ? (mph)
Speed = Threshold ÷ (0.025 * Mass)
-> Speed = 1000 ÷ (0.025 * 5) = 1000 ÷ 0.125 = 8000 (mph)
Finally, all three variations:
1. Threshold = Speed x Mass x 0.025
2. Speed = Threshold ÷ (Mass x 0.025)
3. Mass = Threshold ÷ (Speed x 0.025)