An elite tour de france cyclist can maintain an output of 420 watts during a sustained climb. at this output power, how long would it take a 78 kg cyclist (including the mass of his bike) to climb the famed 1100 m high alpe d'huez mountain stage? neglect any friction.

2002 seconds, or 33 minutes, 22 seconds. First, let's calculate how many joules it will take to lift 78 kg against gravity for 1100 meters. So: 78 kg * 9.8 m/s^2 * 1100 m = 840840 kg*m^2/s^2 Now a watt is defined as kg*m^2/s^3, so a division of the required joules should give us a convenient value of seconds. So: 840840 kg*m^2/s^2 / 420 kg*m^2/s^3 = 2002 seconds. And 2002 seconds is the same as 33 minutes, 22 seconds.