[tex]23h\ 56min\ 4s=\left(23+\frac{56}{60}+\frac{4}{3600}\right)h=\left(\frac{82800}{3600}+\frac{3360}{3600}+\frac{4}{3600}\right)h\\\\=\frac{86164}{3600}h\approx23.93h\\\\L=2\pi R;\ R=3960mi\to L=2\pi\cdot3960mi=7920\pi mi\approx7920\cdot3.14mi\\\\=24868.8mi\\\\v=\frac{24868.8}{23.93}\ mi/h\approx1039.231\ mi/h\leftarrow answer[/tex]
