Joule, uses 1 (thermo-02) Suppose you had 1 kJ (1000 joules) at your disposal. How many degrees Celsius can a liter of water be heated with it? Note: to 1 grams water to 1 degree centigrade to heating, required one about 4.18 [translation unavailable]. How long does a light bulb with 100 watts burn? Which mass can be accelerated from 0 m/s to 1 m/s. Ekin = ½ · m · v2 How many heartbeats or how long can the heart beat? Assuming the power of the heart is 1 watt. In the event of a subsequent exercise ('pentane explosion') 6.8 kJ are released. How many feet could a chemistry teacher be lifted with this energy?

  Exercise: thermo-02    

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Suppose you had 1 kJ (1000 joules) at your disposal.

1. How many degrees Celsius can a liter of water be heated with it?
       Note: to 1 grams water to 1 degree centigrade to heating, required one about 4.18 [translation unavailable].
2. How long does a light bulb with 100 watts burn?
3. Which mass can be accelerated from 0 m/s to 1 m/s. E_kin = ½ · m · v²
4. How many heartbeats or how long can the heart beat? Assuming the power of the heart is 1 watt.
5. In the event of a subsequent exercise ('pentane explosion') 6.8 kJ are released. How many feet could a chemistry teacher be lifted with this energy?

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Solution:

1. Heating to approx. 0.239 ℃
2. The 100 watts indicates that 100 joules per second is needed, so the light bulb can be operated for 10 seconds.
3. E_kin = ½ · m · v²
       1000 J = ½ · x · 1²
       x = 2000 kg
4. 1 [translation unavailable] = 1 [translation unavailable] per [translation unavailable]. So the heart can beat for 1000 seconds (about 1/4 hour).
5. E_pot = m·g·h
       With a chemistry teacher 68 kg (about !)
       with g = 10 m/s²
       h = E_pot /(m·g) = 6800 J/(68 kg·10m/s²⁾ = 10 meters

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