A car

A car weighing 1.05 tonnes, travelling at the maximum speed limit in a village (50 km/h), crashes into a solid concrete barrier. Calculate the height from which the car would have to fall onto a concrete surface to produce the same impact force as in the first case.

Final Answer:

h =  9.6451 m

Step-by-step explanation:

$$\begin{gathered} m=1.05\text{t}\to \text{kg}=1.05\cdot 1000\text{kg}=1050\text{kg} \\ v=50\text{km/h}\to \text{m/s}=50:3.6\text{m/s}=13.88889\text{m/s} \\ g=10{\text{m/s}}^2 \\ v=gt \\ t=v/g=\frac{125}{9}/10=\frac{125}{9\cdot 10}=\frac{125}{90}=\frac{25}{18}\doteq 1.3889\text{s} \\ h=\frac{1}{2}\cdot g\cdot t^2=\frac{1}{2}\cdot 10\cdot {\frac{25}{18}}^2=\frac{3125}{324}\text{m}=9.6451\text{m} \end{gathered}$$

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