What do you think the answer is? I know it do you?
A bowler lifts her bowling ball a distance of 0.5 meters using 35 joules of energy. If, on earth, a 1.0 kilogram mass weighs 9.8 newtons, the mass of the bowling ball used by this bowler is about:
Yeah, 7.14 if you use a calculator.
Reasoning for education's sake -
Work done (or energy used, in joules) is the force used, (in newtons) times the distance traveled.
You know it took 35 joules to move half a metre, so it takes 70 joules to move a full metre.
70 joules is the energy it takes to move 1 metre with 70 newtons of force (which is why joules can sometimes be called Newton/meters).
Now you just need to work out how much mass weighs 70 newtons, which you get from 70 divided by the weight of a kilogram (given to you as 9.8 in the question).
So 70/9.8 is 7.14kg.
Hope that makes sense, since I'd hate to just give the answer to someone's homework without helping them figure it out themselves.
7 kilograms.
am I right