text: energy and joules? energy may be defined as: a the ability to do work    b the product of power and time    c something which can be transferred from one object to another    d all of the above      how much energy is a 75 watt light bulb transferring if it is on for 90 seconds? a 1.2 joules    b 15 joules    c 165 joules    d 6750 joules      how much time is a 100-watt light bulb turned "on" if it transfers a total of 7000 joules of energy? a 70 seconds             b 6900 seconds    c 7100 seconds    d 700,000 seconds      how much power has a lawnmower delivered if it imparts 6000 joules of energy in 20 seconds? a 300 watts             b 5880 watts    c 6020 watts    d 120,000 watts 1.  d, due to basic properties and facts about energy.  in particular, you will use answer b to answer the other three questions.  remember, energy is the product of power and time.  2.  d, because e = pt = (75 w)(90 s) = 6750 j  3.  a, because t = e/p = (7000 j) / (100 w) = 70 s  4.  a, because p = e/t = (6000 j) / (20 s) = 300 w