How does a toy airplane works?

Mach 1 is the speed at which you break the sound barrier. The speed of sound, or Mach 1, at sea level and under "standard condition" is:

• 1,116.4 ft/s
• 340.3 m/s
• 761.2 mph
• 1,225.1 km/h

Read more: How_fast_do_you_have_to_be_moving_to_break_the_sound_barrier